Patent Application
20070181305
1. Field of the Invention
This invention is related generally to milling tools. More particularly, this invention pertains to an apparatus and method for penetrating a tubular body within a wellbore in order to establish a path of fluid communication between inner and outer surfaces of the tubular. In addition, the present invention relates to a milling tool that creates a path of fluid communication from a tubing retrievable subsurface safety valve, to a wireline retrievable subsurface safety valve in order to provide hydraulic pressure to operate the wireline retrievable safety valve.
2. Description of the Related Art
In hydrocarbon producing wells completed with production, there is often a need to cut, punch, drill, mill, dissolve or otherwise remove material in-situ deep in a well. In some cases, cutting the production tubing is desirable. In others, releasing a packer, parting a sleeve, or opening a communication port is the objective. The present invention provides a milling machine that is adapted for use downhole, and may be used in a variety of applications.
A milling machine, in general terms, is a device that has a cutting head rotated against a stationary body. The cutting head includes a blade that cuts against the stationary body, such as a tubular body within a wellbore. Various types of milling machines are known. For example, mill bits are sometimes used in order to cut through a string of casing in order to form a lateral borehole within a wellbore. In such instances, a milling bit is urged downwardly against a diverter tool, such as a whipstock, in order to force the milling bit to grind against the inner surface of the casing. An elongated, elliptical opening, known as a “window,” is thus formed.
A disadvantage to such milling apparatuses is the difficulty in making a cut at a precise location downhole. For example, it is sometimes desirable to penetrate the housing of a tubing-retrievable safety valve in order to create a path of fluid communication from the hydraulic pressure source of the tubing-retrievable safety valve, into the interior bore of the safety valve. This occurs when the tubing-retrievable safety valve has malfunctioned. In such an instance, it is desirable run a second, wireline-retrievable subsurface safety valve (WRSSV) into the wellbore adjacent the defective tubing-retrievable subsurface safety valve (TRSSV), and utilize the hydraulic pressure source of the tubing-retrievable safety valve to operate the wireline-retrievable safety valve. However, there heretofore has been no known mechanical means for accomplishing this milling process.
By way of background, Subsurface Safety Valves (SSVs) are often deployed in hydrocarbon producing wells to shut off production of well fluids in emergency situations. Such SSVs are typically fitted into production tubing in the wellbore, and operate to block the flow of formation fluids upwardly through the production tubing should a failure or hazardous condition occur at the well surface.
The SSV typically employs a valve closure member, or “flapper,” that is moveable between an open position and a closed position. In this respect, the flapper is typically pivotally mounted to a hard seat. When the flapper is in its open position, it is held in a position where it pivots away from the hard seat, thereby opening the bore of the production tubing. However, the flapper is strongly biased to its closed position. When the flapper is closed, it mates with the hard seat and prevents hydrocarbons from traveling up the wellbore to the surface.
The flapper plate of the safety valve is held open during normal production operations. This is done by the application of hydraulic fluid pressure transmitted to an actuating mechanism. A common actuating mechanism is a cylindrical flow tube, which is maintained in a position adjacent the flapper by hydraulic pressure supplied through a control line. The control line resides within the annulus between the production tubing and the well casing, and feeds against a piston. The piston, in turn, acts against the cylindrical flow tube, which in turn moves across the flapper within the valve to hold the flapper open. When a catastrophic event occurs at the surface, hydraulic pressure from the control line is interrupted, causing the cylindrical flow tube to retract, and allowing the flapper of the safety valve to quickly close. When the safety valve closes, it blocks the flow of production fluids up the tubing. Thus, the SSV provides automatic shutoff of production flow in response to well safety conditions that can be sensed and/or indicated at the surface. Examples of such conditions include a fire on an offshore platform, sabotage to the well at the earth surface, a high/low flow line pressure condition, a high/low flow line temperature condition, and simple operator override.
If the safety valve is “slickline retrievable”, it can be easily removed and repaired. However, if the SSV forms a portion of the well tubing, i.e., it is “tubing retrievable”, the production tubing string must be removed from the well to perform any safety valve repairs. Removal and repair of a tubing retrievable safety valve is costly and time consuming. It is usually advantageous to delay the repair of the TRSSV yet still provide the essential task of providing well safety for operations personnel while producing from the well. To accomplish this objective, the tubing-retrievable safety valve is disabled in the open position, or “locked out”. This means that the valve member, i.e., flapper or “flapper plate,” is pivoted and permanently held in the fully opened position.
In normal circumstances, if the well is to be left in production, a WRSSV may be inserted in the well, often in lockable engagement inside the bore within the locked out TRSSV. Because of the insertion relationship, the WRSSV necessarily has a smaller inside diameter than the TRSSV, thereby reducing the hydrocarbon production rate from the well. Locking out the safety valve will not eliminate a need for remediation later, but the lockout and use of the WRSSV will allow the well to stay on production (most often, with a reduced production rate) or perform other work functions in the tubing until the TRSSV can be repaired or replaced.
A novel apparatus and method for locking out a tubing-retrievable safety valve is presented in the pending patent application entitled “Method and Apparatus for Locking Out a Subsurface Safety Valve.” That patent application was filed provisionally on Jul. 12, 2002, and was assigned Ser. No. 60/395,521. A conventional application will be filed under the same title, shortly. That application is incorporated herein fully by reference.
As noted, once a TRSSV is locked out, it is desirable to run in a WRSSV adjacent the TRSSV. In other words, the WRSSV is inserted into the bore of the TRSSV, and then operated in order to provide the safety function of the original TRSSV. This is a more cost-effective alternative to pulling the tubing and attached TRSSV from the wellbore. In order to operate the new WRSSV, a hydraulic fluid source is needed to hold the flapper member of the new WRSSV open. It is preferred to employ the hydraulic flow line already in place for the TRSSV in order to operate the WRSSV. This requires that a communication path be opened between the hydraulic fluid pressure line from the old TRSSV to the new WRSSV.
The present invention is directed to a novel method and apparatus for milling a downhole groove into a tool such as a TRSSV deep in a wellbore. The present inventions are disclosed in the context of creating a path of fluid communication between a TRSSV and a WRSSV disposed therein. However, it is understood that the present inventions are not limited to such use, but that the inventions have many other downhole uses.
Various types of communication devices and methods have been proposed in U.S. Pat. Nos. 3,799,258; 4,944,351; 4,981,177; 5,496,044; 5,598,864; 5,799,949; and 6,352,118. In some of these patents, various additional parts are necessary to enable communication. Where such parts are integral to each and every valve, cost and complexity are obviously added to the valve assemblies. Moreover, modern SSVs are extraordinarily reliable, and such integral communication mechanisms are not used except in a fraction of the total valve population; nevertheless, integral communication mechanisms are included, and add unnecessary cost to most prior art SSV assemblies. Further, integral communication mechanisms may themselves fail to work for various reasons, primarily because the communication mechanisms reside with the SSV's in the harsh downhole environment. Adverse forces include high temperature, high flow rate, sand, corrosion, scale and asphaltine buildup. The forces can cause a failure of the communication mechanism to provide the needed fluid passageway through the TRSSV, and add large and unexpected workover costs.
Other inventors have realized the disadvantages of integral communication mechanisms, and inventions have been disclosed in the US patents discussed below. The trend in these inventions points to a need to remove integral communication mechanisms and requisite structure from the SSV, but none, until the present invention, accomplishes this objective in a reliable, precise, mechanical way.
U.S. Pat. No. 3,799,258 (Tausch '258) discloses a subsurface well safety valve for connection directly to a well tubing for shutting off flow of well fluids through the tubing when adverse well conditions occur. This patent discloses a TRSSV that includes a means for supporting a WRSSV in the event that the first safety valve becomes inoperative. Tausch '258 is instructive wherein the insertable relationship between the TRSSV and the WRSSV is clearly depicted. Tausch '258 provides a fluid control line extending from the surface to a first safety valve. The first safety valve includes a port communicating with the control line and having a shearable device. The shearable device initially closes the port; however, when sheared, it opens the port to allow fluid communication between the hydraulic flow line and the inner bore of the first safety valve. From there, fluid communicates with and controls a second safety valve supported in the first valve bore. A disadvantage to the arrangement of Tausch '258 is that the shearable means can be accidentally sheared during slickline operations, causing hydraulic pressure loss and a malfunction of the first safety valve, i.e., a TRSSV. Further, the device requires a moving sleeve that can become stuck and fail after years of residence in an oil or gas well. Finally, the moving sleeve adds cost to each and every well, whether or not the primary SSV ever fails.
U.S. Pat. No. 4,981,177 (Carmody '177) provides a device integral to a downhole tool, such as a safety valve or a stand-alone nipple. The device has a tubular housing with an axially extending bore being provided along the housing. A radially extending recess is provided in the internal bore wall of the housing, encompassing the axially extending bore. A control fluid pipe is passed through the bore and the recess. A cutting tool is mounted for radial movements in the recess and is actuated by downward jarring forces imparted by an auxiliary tool. When the cutting tool is actuated, the control pipe is severed, and the lower severed end portion of the control pipe is concurrently crimped to close such end portion. This device again adds cost to each and every valve in each and every well, whether or not the primary SSV ever fails. Moreover, the device incorporates moving parts that can become stuck and fail after years of residence in an oil or gas well.
U.S. Pat. No. 4,944,351 (Eriksen, et al. '351) provides a similar method and apparatus to Tausch '258 and Carmody '177. This device features an internally projecting integral protuberance in the bore of the original safety valve housing. A connecting fluid conduit is provided between the interior of the protuberance and the existing control fluid passage. A cutting tool is also integral to the TRSSV, and is mounted on an axially shiftable sleeve disposed immediately above the protuberance. The axially shiftable sleeve is manipulated by a slickline tool that is inserted in the bore of the TRSSV. Movement of the sleeve causes the cutting tool to remove the protuberance, and thus establish fluid communication between the control fluid and the internal bore of the TRSSV housing. Continued well control is assured as control fluid pressure supplied through the opening provided by the severed or removed protuberance operates an inserted WRSSV. However, the protuberance can be accidentally sheared or otherwise damaged during slickline operations, causing hydraulic pressure loss and a malfunction of the TRSSV. Further, the device requires a moving sleeve that can become stuck and fail after years of residence in an oil or gas well. The sleeve is provided in every valve whether used or not, and adds cost to the device.
U.S. Pat. Nos. 5,496,044 (Beall '044) and 5,799,949 (Beall '949) recognize the need to remove structure from the TRSSV. The devices of Beall '044 and Beall '949 have internal and external metal-to-metal radially interfering seals that provide an annular chamber. Communication with the annular chamber is established by a slickline tool adapted to punch a hole through the wall of the TRSSV and into the annular chamber. The annular chamber is necessary because the slickline punch tool cannot radially orient to a hydraulic piston hole formed in the TRSSV. The hydraulic chamber undesirably adds a potential leak path if the radially interfering metal-to-metal seals leak. This can cause the premature failure of the TRSSV. The existence of the annular chamber also adds an additional thread to the TRSSV, and the cost associated therewith to each and every TRSSV.
U.S. Pat. No. 5,598,864 (Johnston, et al. '864) discloses a subsurface safety valve, i.e., TRSSV, that has a plug inserted within an opening in the valve housing. This opening is in fluid communication with the piston and hydraulic cylinder assembly of the valve. The plug is adapted to be displaced from the opening to lock out the tubing-retrievable safety valve, and to establish secondary hydraulic fluid communication with an interior of the safety valve in order to operate a secondary WRSSV. The WRSSV is deployed in the primary valve (TRSSV) by slickline, and engages a profile in the TRSSV. Downward force to the deployed WRSSV causes a bolt to shear, thereby pulling the plug out of the opening in the TRSSV and establishing communication. This integral arrangement again adds cost to each and every valve in each and every well, whether or not the primary SSV ever fails. Moreover, the device adds parts that can become stuck or fail after months or years of idle residence in an oil or gas well.
Next, U.S. Pat. No. 5,201,817 (Hailey '817) provides an improvement for a downhole cutting tool otherwise used for many years. This device is used to cut through oilfield tubulars, such as tubing string. The Hailey '817 patent mentions the cleanout of debris, cement, mud, and other materials within a tubular. The cutting action of this tool is rather coarse and cannot be carefully controlled so as to not damage the pressure integrity of a SSV or other downhole device.
Finally, U.S. Pat. No, 6,352,118 (Dickson '118) recognizes the positive attributes of having no additional integral SSV parts to enable communication. Dickson '118 describes a tubular apparatus that delivers a dispersed jet of fluid referred to as a “chemical cutter.” The tubular tool is landed within a TRSSV, and the chemical fluid is then directed against the inner wall of the TRSSV. In operation, the chemical acts against the material of the TRSSV in order to form an opening that provides fluid communication from between the hydraulic fluid source for the valve, and the inner bore.
“Chemical cutters” have been used for decades in the oil industry to “cut” tubing, and are indeed a well-known idiom in the oilfield lexicon. However, a more technically accurate definition is “a chemical reaction of an acid and a base to dissolve a portion of a tool.” The method of Dickson '118 relies on placing a strong acid or other reactant in a local area until the base material is dissolved in situ. This dissolution ostensibly gives an operator the desired result of establishing a communication pathway through the TRSSV. The downside of the apparatus of Dickson '118 is the reliability of the dissolution on a variety of common SSV materials, and the uncertainty of containment of the reaction. For example, if the acid dissolves through the pressure containing body of the TRSSV or contacts the flow tubes, the planned workover can no longer be completed. The completion must be removed from the well, creating expenses of potentially millions of dollars. If the value of the remaining hydrocarbons in the reserve do not justify total re-completion of the well, the result could be a complete loss of the well.
In fairness, the Dickson '118 patent mentions alternatives to chemical cutters. These are listed as “a mechanical cutting tool” and an “explosive cutting mechanism.” However, Dickson '118 never discloses or describes any embodiment or means for utilizing either a mechanical cutting tool or an explosive cutting arrangement within a TRSSV. To the knowledge of the inventors herein, such tools have remained unknown.
There is a need, therefore, for a mechanical communication tool that requires no additional integral SSV parts to enable communication. There is a further need for a communication tool that can be deployed by slickline, and mechanically establishes a fluid communication path from the hydraulic chamber of a primary TRSSV to a secondary WRSSV by milling a groove of a controlled depth in a precise location, and can be used to establish communication in any type of safety valve.
A note about the terms “slickline” and “wireline” is in order: Historically, the term “wireline” has been used to describe all tools lowered in a well that hang on a small diameter wire. Developments in the last several years have some tools being lowered in the well on an “electric line”, where the line not only provides hanging support for the tools, but also provides power and/or communication channels for an electrically operated tool. Often these tools are suspended by braided umbilical cables, and in the most current oilfield vernacular, have also come to be known as “wireline” tools.
Most tools lowered in wells today are mechanical in nature, and require no electric power to operate. In the past, these tools were known as “wireline” tools. However, with the advent of electrical tools, the mechanical tools are now commonly referred to as “slickline” tools rather than “wireline” tools.
One embodiment of the present invention is a “slickline tool” because it is deployed with a battery stack and requires no external power for operation. Typically, slickline operations are less complex than wireline. However, it is obvious that the present invention could also be configured to be deployed on an electrically charged “wireline”. Therefore, for purposes of the present application, the term “slickline” includes cables, electrical lines and wirelines of whatever type.
The present invention presents an apparatus and method for forming an opening within the housing of a downhole tool, such as a tubing-retrievable subsurface safety valve (TRSSV). The apparatus defines a milling tool having a housing system, a cutting system, a drive system, and an actuation system. The milling tool is configured to be landed within the inner bore of a TRSSV, and is actuated so as to shave or otherwise mechanically form an opening through the inner bore of the TRSSV. In this manner, a pathway of communication is formed within the TRSSV between the hydraulic chamber (or fluid source) and the inner bore.
As noted, the milling tool first comprises a housing system. The housing generally defines an elongated tubular body for housing components of the tool. In one aspect, the housing system is comprised of a series of sub-housings generally disposed end-to-end. However, in one aspect the housing system is configured to permit a degree of telescopic collapsing of the housing system during the tool actuation process.
Next, the milling tool comprises a cutting system. The cutting system includes one or more blades that are disposed on a cutter head. The cutter head is rotated by a shaft in order to rotate the blades within the TRSSV. In one arrangement, the blades are biased outward so as to engage an inner surface of the housing for the tubing-retrievable safety valve when the cutting system is rotated.
Next, the milling tool comprises a drive system. The drive system is generally comprised of a rotary motor, and a shaft system rotating in response to the motor. The motor may be line powered via a wireline, or may be battery operated. In one aspect, a controller is also provided for regulating rotary movement of the motor and attached shaft system. The shaft system connects the motor and its gearbox to the cutter head further down the tool.
Finally, the milling tool has an actuation system. The actuation system actuates the motor system once the milling tool is landed into the TRSSV downhole. In one aspect, the actuation system is interlocked with one or more safety features, such as a delay timer and a pressure sensor. In this way, the actuating system will not place the motor of the drive system in electrical communication with the power source, e.g., batteries, until one or more conditions (such as a five minute delay, or a temperature of 300° F.) are reached.
A method is also provided for forming an opening within a tubing-retrievable subsurface safety valve. In this respect, a milling tool of the present invention is run into a wellbore. The apparatus may be run either at the lower end of a wireline, or at the lower end of a string of coiled tubing. The apparatus is lowered within the production tubing of a hydrocarbon wellbore, and landed in a landing profile of the TRSSV. This places the cutting system for the milling apparatus at the precise location needed within the TRSSV for milling the communication opening. It is preferred that the TRSSV be permanently locked out prior to running the milling tool into the wellbore. However, the scope of the present invention permits the milling and communication process to take place before the primary safety valve is locked out.
After the milling tool is located within the TRSSV, the actuation system is actuated. In one aspect, the actuation system defines a magnetically sensitive reed switch that closes an electrical circuit when placed in sufficient proximity with a magnet (or other magnetic force). Initiation of the actuation system actuates the drive system within the tool. This, in turn, transmits torque through the shaft system and to the connected cutting apparatus. A pathway for communication between the hydraulic flow line for the TRSSV and the inner bore of the TRSSV can then be formed. Afterwards, the milling apparatus is pulled out of the safety valve and from the production tubing within the hydrocarbon wellbore.
In operation, the communication tool of present invention may be used by lowering the tool into a well, locating the tool in the area to be milled, locking the tool in position, starting the motor, deploying the cutter head, milling a groove to establish fluid communication, and removing the downhole milling tool from the well.
So that the manner in which the above recited features of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIGS. 3A(1)-A(2) present a cross sectional view of the milling tool of
FIGS. 4A(1)-A(2) provide a cross sectional view of a portion of the milling tool of
FIGS. 5A(1)-A(2) show a new cross-sectional view of the milling tool of the present invention, in the embodiment of FIGS. 4A(1)-A(2). This view shows the tool in a second position. Downward force is being applied through the housing system of the tool, causing a shear pin in a shear pin housing to shear from the locating mandrel. This allows the locating mandrel and attached locking dogs to move downward in the tool such that the locking dogs are now at the level of the locating dogs.
FIGS. 6A(1)-A(2) provide a new cross-sectional view of the milling tool of FIGS. 4A(1)-A(2). This view shows the next step in the tool actuation process. Here, the housing system is beginning to telescopically collapse. The switch housing is seen being received within a sliding sleeve, drawing a rod and attached magnet closer to a reed switch within the switch housing.
FIGS. 7A(1)-A(2) present another cross-sectional view of the milling tool of FIGS. 4A(1)-A(2). The next step in the tool actuation process is provided. Further telescopic compression of the housing system has taken place, bringing the magnet closer to the reed switch. The reed switch is now magnetically initiated and is prepared to actuate the drive system of the tool. Also, a bearing housing and load ring have contacted the top of a set of cones.
FIGS. 8A(1)-A(2) demonstrate an additional cross-sectional view of the milling tool of FIGS. 4A(1)-A(2). A next step in the tool actuation process is again provided. Here, downward force is being applied through the bearing housing and load ring in order to drive the cones under a set of buttons.
FIGS. 9A(1)-A(2) provide is a cross-sectional view of the milling tool of FIGS. 4A(1)-A(2), and showing the next sequential step in the tool actuation process after FIGS. 8A(1)-A(2). In this step, the motor has been actuated, and is rotating the shaft system of the tool. It can be seen that a release sleeve has moved back from within a surrounding cutter head housing, thereby exposing the blades. The blades are biased outward, and have engaged the housing of the safety valve.
FIGS. 10A(1)-A(2) provide yet another cross-sectional view of the milling tool of FIGS. 4A(1)-A(2). The milling operation is completed, and tensile force is now being applied through the tool housing system in order to withdraw the milling tool from the wellbore. The cones are being lifted, causing the buttons to recede from the surrounding valve housing. In addition, the cutter head and attached blades are being pulled into the cutter head housing.
FIGS. 11A(1)-A(2) provide a final cross-sectional view of the tool of FIGS. 4A(1)-A(2). Here, the milling tool is being lifted out of the TRSSV, and from the wellbore. The eccentric cut formed in the valve housing as a result of the milling operation is seen. More specifically, an opening is seen through the housing, providing fluid communication between the hydraulic chamber of the TRSSV and the inner bore.
As will be described fully herein, the purpose of the milling tool 100 is to form an opening in the housing of a downhole tubular. In the example presented herein, the downhole tubular defines a tubing-retrievable safety valve. However, it is understood that the milling tool 100 may be used to mechanically form an opening in any downhole tubular body. In addition, the present invention will be described in connection with a tubing retrievable surface controlled subsurface flapper type safety valve, where it is operationally desirable to establish hydraulic communication with a slickline inset valve. It will be understood that the present invention may be used with other types of subsurface safety valves, including those having different type valve closure members such as balls, and those having different type actuation methods, such as subsurface controlled (i.e., velocity, dome charged, and injection) safety valves.
As will be shown, the milling tool 100 of the present invention comprises a housing system, a cutting system, a drive system, and an actuation system. Optionally, the tool 100 also provides an anchoring system for anchoring the tool housing 110 within a surrounding valve housing 52 so as to prevent rotation of the tool housing 110 during tool 100 actuation. Further, the tool 100 includes optional locating means for providing a more precise ability to locate the milling tool 100 at a desired location within the subsurface safety valve 50. These various systems are described and numbered below in connection with the cross-sectional views of the milling tool 100.
As noted above, the milling tool 100 first comprises a housing system 110. As shown in the isometric view of
The tool 100 has an upper end 102 and a lower end 104. The upper end 102 serves as a connector to a run-in tool. The run-in tool may be for example, a slickline or a string of coiled tubing. In one aspect, the upper end 102 connects to a slickline stem used in connection with oil field jars, such as spang jars (not shown). The jars are used to hammer downwardly upon a tool within the wellbore by alternately raising the slickline and a connected weighted wire line stem, and dropping the slickline and connected weighted wire line stem upon a steel bar.
The first sub-housing is seen near the upper end 102 of the tool 100. This sub-housing is a thermal housing 120. The thermal housing 120 defines an elongated tubular body. The upper end of the thermal housing 120 is the connector 102 described above. In the preferred arrangement, the thermal housing 120 serves as a housing for certain components for the milling apparatus 100.
The next housing is a motor housing 130. The motor housing 130 is disposed immediately below the thermal housing 120. The motor housing 130 is connected to the thermal housing 120 by a flask connector 126. The configuration and purpose of the flask connector 126 will be described in greater detail below, in connection with FIGS. 4A(1)-A(2).
Below the motor housing 130 is a series of additional sub-housings. These include a switch housing 140, a hook body housing 160, a button housing 170, a no-go body housing 180, a shear pin housing 190 and a cutter head housing 210. Intermediate the switch housing 140 and the hook body housing 160 is a sliding sleeve 155. The sliding sleeve 155 receives the switch housing 140 when the tool 100 is actuated, permitting some telescopic collapsing of the tool 100 along its length.
The configuration of the housing system 110 for the tool 100 is seen in greater detail in
A set of buttons 520 is also seen along the housing 110. The buttons 520 are more specifically disposed along the button housing 170. As will be shown in connection with FIGS. 4A(2) and 4D, the buttons 520 are urged outwardly from the button housing 170 after the tool 100 is landed within the TRSSV 50. The buttons 520 will engage the surrounding TRSSV 50 body in order to serve as a torque anchor while the milling operation is being performed.
Also visible in
Finally, two sets of screws 157, 167 are seen along the housing 110 in
FIGS. 3A(1)-A(2) present a cross-sectional view of the milling apparatus 100 of
One of ordinary skill in the art will recognize the temperature-sensitive nature of the controller 320. For this reason, the controller 320 and connected batteries 315 are housed within a thermal housing 120. The thermal housing 120 is manufactured as a Dewar flask to house the controller 320, meaning that it is constructed from concentric metal tubes having a vacuum therebetween. The vacated space may be filled with a non-thermally conductive powder or other material to mechanically support the tubes. In one aspect, a Teflon-filled material is used in the vacated space to provide a ruggedized insulator. The controller 320 can thus be immersed into an environment of 300° F. for an extended period of time without thermal damage to the controller 320 or batteries 315.
It should be noted that a plurality of batteries 315 are presented in
Moving now to FIGS. 4A(1)-A(2), FIGS. 4A(1)-A(2) provide a cross-sectional view of a portion of the milling tool 100 of
In FIGS. 4A(1)-A(2), the actuating system 330 has not been initiated. For this reason, the drive system 300 is not driving the shaft system 400 in order to turn the blades 218 of the cutting system 200. These steps will be described incrementally in connection with FIGS. 5A(1) through 9A(2). In one or two instances, tool parts are shaded in these views in order to indicate energized or moving parts.
Visible first in
A connector retainer 128 is also seen in
The connector 126 houses an electrical connector 318 having electrical pins 316 on opposite ends thereof. In one arrangement, the electrical connector 318 is a 10-pin hermaphroditic connector. At one end, the electrical connector 318 receives a reciprocal connector from the thermal housing 120 in order to provide electrical communication with the batteries 315 and the controller 320. At an opposite end, the electrical connector 318 receives wires 317 that provide electrical communication with the motor 310 and the actuating system 330.
Below the connector 126 is the connected motor housing 130. The motor housing 130 defines an elongated tubular body having a top end 132 and a bottom end 134. As the name implies, the motor housing 130 houses the motor 310 of the drive system 300. In one aspect, the motor 310 defines a brushless DC powered rotary motor. In one aspect, electrical power is supplied from THE stack of NiCad batteries 315 that are housed within the thermal housing 120. The motor 310 is shown somewhat schematically in
The motor 310 is connected to a gear box 312. Where a high RPM electric motor is used, a gearbox is employed to reduce the RPMs. The gear box 312, in turn, is connected to the output shaft 410, which becomes part of the shaft system 400. As will be described, the shaft system 400 connects the motor 310 to the cutting system 200, e.g., cutter body 480.
The motor housing 130 includes a cavity area 136 between the housing 130 and the motor 310 itself. The cavity area 136 is optionally filled with a dielectric fluid, such as silicon oil. As will be described below, the dielectric fluid is generally pressurized to wellbore pressure. A lower portion of the motor housing cavity 136 includes a switch 330. In the preferred arrangement for the actuating system 330, the switch forms an integral part of the actuating system 330. Hence, the two parts share a reference number. In one aspect, the switch 330 defines a reed switch which is magnetically sensitive. As will be discussed further below, the switch 330 closes when it comes into proximity with a magnetic force, such as a magnet (shown at 332). This will serve to close the circuit for the electrical circuitry of the drive system 300, allowing electrical current to flow through the wires 317 in order to actuate the drive system 300 for the tool 100. In one aspect, the reed switch 330 is potted into the cavity 136 using a flexible epoxy potting compound
Below the motor housing 130 is a switch housing 140. The switch housing 140 also has an upper end 142 and a lower end 144. The top end 142 of the switch housing 140 is threadedly connected to the bottom end 134 of the motor housing 130. The switch housing 140 has an inner bore for receiving a drive shaft 420. The drive shaft 420 is driven by the output shaft 410 from the motor 310 and gear box 312. The switch housing 140 also has a pair of cavities 146, 148. The first cavity 146 houses a pressure balancing piston 145, while the second cavity 148 receives a rod 340.
The first cavity 146 is in fluid communication with the annular region 136 of the motor housing 130. Thus, the first cavity 146 of the switch housing 140 is also filled with a dielectric fluid. The fluid is placed above the pressure balancing piston 145. Again, the dielectric fluid is a nonconductive type fluid, such as silicon oil. The portion of the first cavity 146 opposite the pressure balancing piston 145 is exposed to wellbore pressure. Thus, the piston 145 serves to pressure balance the inside of the housing 110 around the flask connector 126, while preventing caustic wellbore fluids from contacting the motor 310 and connected hardware, e.g., gear box 312. The floating piston 145 also compensates for temperature increases of the dielectric fluid caused by downhole conditions, and by heat dissipated by the motor 310. This ensures that there is no differential pressure acting on the sealed shaft o-ring so that the motor 310 does not have to overcome increased drag caused by the differential.
As noted, the second cavity 148 for the switch housing 140 houses a rod 340. The rod 340 defines an elongated rod having an upper end 342 and a lower end 344. The upper end 342 includes a strong permanent magnet 332. Thus, the rod 340 and magnet 332 form a part of the actuating system 330. The lower end 344 defines a hook. As will be described below, the hook 344 connects to a hook body housing 160.
As with the balancing piston 145 within the first cavity 146, the rod 340 within the second switch housing cavity 148 is moveable. In this respect, when the milling tool 100 is landed into the primary safety valve 50, force is applied downward along the thermal housing 120, motor housing 130, and switch housing 140 of the tool 100. As will become clearer from the additional description of the tool 100 below, this serves to telescopically collapse the housing 110, causing the rod 340 to move upward within the second cavity 148 of the switch housing 140. As the rod 340 moves axially upward within the switch housing 140, it approaches the reed switch 330 within the cavity 136 of the motor housing 130. The reed switch 330 closes the electrical circuitry of the drive system 300, allowing current from the batteries 315 and the controller 320 through the electrical connector 318, via wires 317, and to the motor 310.
As a safeguard, an interlocking means may be designed into the actuating system 330. For example, a timer may be incorporated into the software for the controller 320 in order to require a delay, such as a delay of 5 minutes, after the reed switch 330 closes the circuit. Other safeguards may be build into the system as well. For example, a temperature sensor may be exposed along the length of the housing 110. The temperature sensor reads downhole temperature as the tool 100 is lowered into the wellbore. The controller 320 would then include electronics that monitor temperature readings. In one aspect, a temperature reading of at least 300° would be required before the motor 310 is actuated.
Other interlocking features may be included within the tool 100 as well. These include motion sensors and pressure sensors. For example, an optional accelerometer pack (not shown) can be wired in series with the reed switch 330 for added assurance that the controller 320 will not receive an enable signal until the reed switch 330 is closed and the entire tool 100 has come to rest. Such features again serve to prevent premature actuation of the drive system 300 and attached cutting system 200 for the tool 100.
Returning now to
The housing system 110 next comprises a hook body housing 160. The hook body housing 160 also comprises an upper end 162 (seen in
The housing system 110 for the tool 100 next comprises a button housing 170. The button housing also comprises a top end 172 and a bottom end 174. In the arrangement of
As noted, the milling tool 100 includes an optional anchoring means 500. In one aspect, the anchoring means 500 comprises a plurality of cones 510 and a plurality of matching buttons 520. In the arrangement of
The button housing 170 includes a plurality of recesses 176. A recess 176 is seen best in
The housing system 110 for the tool 100 next comprises a no-go body housing 180. The no-go body housing 180 has an upper end 182 that is threadedly connected with the lower end 174 of the button housing. The no-go body housing 180 further has a lower end 184. As with other sub-housings, the no-go body housing 180 defines a tubular body. The no-go body housing 180 has a profiled outer surface. The profiled outer surface becomes a part of the locating means 600 for the tool 100. More specifically, a no-go shoulder 680 is formed on the outer surface of the no-go body housing 180. As described above, the no-go shoulder 680 serves as a locator for landing into a matching shoulder along the inner surface of the housing 52 for the surrounding TRSSV 50.
As with the button housing 170, the no-go body housing 180 also has a plurality of recesses 186. The no-go body housing recesses 186 are configured to receive respective locating dogs 650. The locating dogs 650 are also part of the locating means 600 for the tool 100. When the milling tool 100 is landed within the TRSSV 50, and as downward force is transmitted through the tool 100, the locating dogs 650 are urged outwardly from the recesses 186 of the no-go body housing 180 into a corresponding radial recess 53 within the valve housing 52. This process will be described in additional detail below.
The housing system 110 for the milling tool 100 next comprises a shear pin housing 190. The shear pin housing 190 is connected to the lower end 184 of the no-go body housing 180. As the name implies, the shear pin housing 190 houses a plurality of shear pins 197. The shear pins 197 are received within respective radially disposed recesses 196 of the shear pin housing. The shear pins 197 are further held within the respective recesses 196 by one or more garter springs 193. In this manner, the pins 197 are biased to more inward within the recesses 196. The inward movement of the shear pins 197 will be described in additional detail below.
The housing system 110 for the milling tool 100 next comprises a cutter head housing 210. The cutter head housing 210 has a top end 212 and a lower end. The top end 212 of the cutter head housing 210 is connected to the shear pin housing 190 opposite the no-go body housing 180. The cutter head housing 210 is dimensioned to receive an elongated release sleeve 230. The release sleeve 230 is a part of the cutting system 200 for the tool 100. The cutter head housing 210 has an inner surface which is threaded. Likewise, the release sleeve 230 has an outer surface that is threaded. As will be described in additional detail below, the release sleeve 230 is driven upward within the cutter head housing 210 along the matching threads when the drive shaft system 400 and connected release sleeve 230 are rotated within the cutter head housing 210.
As noted above, the housing system 110 for the milling tool 100 is dimensioned to receive the motor 310 and connected shaft system 400 for the tool 100. The motor 310 and gear box 312 serve to transmit torque to the shaft system 400. The shaft system 400, in turn, serves to transmit torque to the cutting means 200 for the tool 100. This is accomplished in the following manner.
First, the gear box 312 has a connected output shaft 410. The output shaft 410, in turn, is connected to one or more additional shafts. In the arrangement of
The lower end 144 of the switch housing 140 is threadedly connected to a bearing housing 150. As the name indicates, the bearing housing 150 houses a bearing system that permits the shaft 400 to rotate. In one aspect, the bearings include a needle roller bearing 432 and a pair of needle thrust bearings 434. The needle roller bearings 432 serve to take up side load, while the needle thrust bearings 434 take up axial load. The needle roller bearings 432 and the needle thrust bearing 434 reside between the bearing housing 150 and the shaft 400. At this level, the shaft 400 defines an upper drive shaft extension 430. Thus, the upper drive shaft extension 430 is connected to a lower end of the drive shaft 420.
Below the lower drive shaft extension 440, a head cap 450 is provided. The head cap 450 has an upper end 452 and a lower end 454 (shown in
The shaft system 400 for the tool 100 finally comprises a spring shaft 470. The spring shaft 470 connects the cutting head drive shaft 460 to the cutter body 480 by a pair of threaded connections. The spring shaft 470 is disposed within a biasing spring 476. The action of the biasing spring 476 will be described in additional detail below.
As noted above, the milling tool 100 of the present invention also comprises a cutting system 200. The cutting system 200 of the present invention presents a novel means for forming an opening within the housing 52 of a tubing-retrievable safety valve 50. More specifically, a mechanical way for providing fluid communication between the hydraulic fluid system of the TRSSV at a precise location of the inner bore of the valve 50 is provided. Heretofore, a means for providing such a precision cut has been unknown in the art.
The cutting system 200 is rotated by the drive system 300. In this respect, the cutter body 480 of the cutting system 200 is connected to the shaft system 400. The cutter body 480 as seen in
Intermediate the upper 482 and lower 484 portions of the cutter body 480 is one or more blades 218. In the arrangement of
The blades 218 are biased to move outward. In order to drive the blades 218 outward, a downward force is applied to the lobes 202 of the blades 218. To provide the desired downward force, a choke pin 220 is first provided. The choke pin 220 resides within a choke box 215. The choke box 215 has an upper end 214 that is in contact with the biasing spring 240, mentioned earlier. The spring 240 biases the choke box 215 to act downwardly. The choke box 215, in turn, is able to act downwardly on the choke pin 220, causing the blades 218 to pivot about their respective hinges 216.
It should be noted that the configuration of the choke pin 220 within the choke box 215 provides a unique means for adjusting the degree to which the cam lobes 202 are flanged outward. In this respect, the choke pin 220 is threadedly inserted into the choke box 215. The farther the choke pin 220 is inserted into the choke box 215, the less the cam lobes 202 and attached blades 218 are flanged out.
In the run-in position shown in
The cutter head housing 210 includes a keyway 213 running along its length. The keyway 213 receives a spline (not shown) within the release sleeve 230. The release sleeve 230 rotates within the cutter head housing 210 when the actuating system 300 of the tool 100 is actuated. The release sleeve 230 rides upward within the cutter head housing 210, and along the keyway 213. In this manner, the release sleeve 230 is able to back away from the blades 218 of the cutting system 200.
At the lower end 104 of the milling tool 100, an optional junk basket 700 is provided. The junk basket 700 has a nose 704 at a lower end. An upper end 702 of the junk basket receives the lower portion 484 of the cutter body. Sufficient space is provided between the upper portion 702 of the junk basket and the lower portion 484 of the cutter body 480 in order to define a receptacle. As metal shavings are taken from the inner bore of the safety valve 50, the shavings fall into the receptacle 702 formed by the upper portion of the junk basket 700. In this manner, metal shavings can be cleaned from the wellbore after the tool 100 is pulled. An optional magnet (not shown) may be included within the receptacle 702.
The milling tool 100 in the present invention also comprises locating features 500. The no-go shoulder 680 along the no-go body housing 180 has already been described. This feature is desirable to provide the most precise placement of the cutting blades 218 within the safety valve housing 52. However, additional features may also be provided.
First, a series of mandrels 610, 630, 660 are provided. Each mandrel 610, 630, 660 defines a tubular body having a top end and a bottom end. Further, each mandrel 610, 630, 660 is nested between the housing system 110 and the shaft system 400 for the tool 100.
The first mandrel is the setting mandrel 610 (seen in FIGS. 3A(2) and 4A(2)). The setting mandrel 610 has an upper end 612 and a lower end 614. The upper end 612 of the setting mandrel 610 is connected to the bearing housing 150 opposite the switch housing 140. From there, the setting mandrel 610 extends down below the cones 510 and the buttons 520. The outer diameter of the setting mandrel 610 constrains the cones 510 from moving into the button housing 170. The bottom end 614 of the setting mandrel 610 is disposed adjacent the top end of the cutter mandrel 630. As will be described in further detail below, the setting mandrel 610 moves downward relative to the cutter mandrel 630 as additional downward force is transmitted through the tool 100.
In the run-in position for the tool 100, the setting mandrel 610 is disposed generally within the hook body housing 160 and the button housing 170. Further, the setting mandrel 610 is generally disposed around the lower drive shaft extension 440 and the head cap 450. Of interest, a load ring 616 is placed on the outer surface of the setting mandrel 610 above the cones 510. The load ring 616 will act downwardly on the cones 510 when downward force is transmitted through the tool 100.
The second mandrel of the tool 100 is the cutter mandrel 630. The cutter mandrel 630 has an upper end 632 (numbered in
Finally, the third mandrel is a locating mandrel 660. The locating mandrel 660 is disposed around the outer surface of the cutter mandrel 630. The locating mandrel 660 carries the ratchet 620. In addition, the locating mandrel 660 carries a plurality of locking dogs 640.
The locating mandrel 660 receives one or more shear pins 662. It can be seen in the view of
An additional tool is seen disposed along the lower end 634 of the cutter mandrel 630. This is a cutter mandrel head 670. The cutter mandrel head 670 extends below the cutter mandrel 630, and resides between the cutting head drive shaft 460 and the surrounding shear pin housing 190. A needle roller bearing 672 and needle thrust bearings 674 (numbered in
It should be noted that the cutter mandrel head 670 does not rotate relative to the shear pin housing 190. To this end, a keyed connection is provided between the cutter mandrel head 670 and the shear pin housing 190.
It is also noted that the cutter mandrel head 670 has a plurality of recesses 676. It will be noted later in
An optional backlash system 800 is finally provided for the milling tool 100 of the present invention. The backlash system 800 serves to absorb the impact of the tool 100 as the tool 100 is landed in the tubing-retrievable safety valve 50, and as the tool 100 is otherwise jarred in place. First, a plurality of wave washers 802 are loaded into the tool 100 below the bearing housing 150. It can be seen from
Moving now to FIGS. 5A(1)-A(2), FIGS. 5A(1)-A(2) present a new cross sectional view of the milling tool 100 of FIGS. 4A(1)-A(2). This view shows the tool 100 in a second position. The milling tool 100 remains landed within the housing 52 of the tubing-retrievable valve 50. Downward force is now being applied through the housing system 110 of the tool 100.
First, it can be seen that shear pin 662 temporarily connecting the no-go body housing 180 to the locating mandrel 660 has been sheared. Shearing takes place in response to the jarring down action on the tool 100. Shearing of the pin 662 allows the locating mandrel 660 to move downward relative to the housing system 110 of the milling apparatus 100. As the locating mandrel 660 shifts downward, it pushes the attached locating dogs 650 downward. In
In
In the view of
To this point, the locking dogs 640 have temporarily locked the locating mandrel 660 to the cutter mandrel 630. However, when the locking dogs 640 reach the depth of the outwardly popped locating dogs 650, the locking dogs 640 are also free to move outwardly, at least to a small extent. In this manner, the locating mandrel 660 is no longer locked to the cutter mandrel 630, and the cutter mandrel 630 is free to move relative to the locating mandrel 660.
Next in
It should also be noted that downward force applied to the tool 100 through the spang jars has initiated the telescopic shortening of the tool 100. The motor housing 130 and the switch housing 140 have begun to move downward relative to the connected lower housing portions, e.g., hook body housing 160, and button housing 170. It can be seen that the sliding sleeve 155 has received a portion of the switch housing 140. Downward movement of the switch housing 140 has caused a downward force to be applied to the bearing housing 150, which in turn acts downwardly against the setting mandrel 610 and the locating mandrel 660.
Finally, with respect to
Moving now to FIGS. 6A(1)-A(2), FIGS. 6A(1)-A(2) present the next step in the cutting process for the milling apparatus 100 of the present invention. FIGS. 6A(1)-A(2) again present a cross sectional view of the milling apparatus 100, as shown from the flask connector 126 downward. It will be seen in this view that the sliding sleeve 155 has continued to receive the switch housing 140, and attached upper components of the tool 100, e.g., motor housing 130 and motor 310. Downward force applied through the motor housing 130 and switch housing 140 has urged the bearing housing 150 downward. This, in turn, has transmitted downward force against the setting mandrel 610 and connected load ring 616. It can be seen now in
Next from
It can next be seen from
Finally, it can be seen in
Moving now to FIGS. 7A(1)-A(2), FIGS. 7A(1)-A(2) present the next step in the actuation process for the milling tool 100 of the present invention. Telescoping collapse of the housing system 110 is no longer taking place. As noted from
This is not to say that compressive forces are no longer being applied through the tool. The spang jars continue to transmit downward force through the motor housing 130 and the switch housing 140. This, in turn, transmits force through the bearing housing 150 and against the setting mandrel 610 and connected load ring 616. It can be seen in
Also of significance from
FIGS. 8A(1)-A(2) provide a next step for actuating the milling tool 100 of the present invention. In this view, the load ring (darkened at 616), which is disposed about the setting mandrel 610, continues to apply a downward load against the cones 510. It can be seen in
It should again be noted that compressive load continues to be applied by the spang jars and downward through the motor housing 130 and the switch housing 140. In
FIGS. 9A(1)-A(2) present the next chronological step in the actuation process for the milling tool 100 of the present invention. FIGS. 9A(1)-A(2) provide a cross-sectional view of the tool 100, in one embodiment. Again, the tool 100 is only shown from the flask connector 126, downward. In this view, the drive system 300 has been actuated. This means that the motor 310 is now being driven by the batteries (show at 315 in
Rotation of the shaft system 400 also causes the release sleeve 230 to retract along the cutter body 480. This is due to the threaded and splined arrangement described above. In the view of
In the cut-away view of
The tool 100 on the present invention again includes an optional junk basket feature 700. The junk basket 700 provides a receptacle 702 that catches metal shavings generated during the milling process.
Other aspects of the invention demonstrated within FIGS. 9A(1)-A(2) are worth noting. First, the ratchet 620 continues to engage the cutter mandrel 630. This keeps the buttons 520 energized. However, it can be seen that the wave washers 802 in the backlash system 800 have relaxed a bit. This allows a release of a portion of the jarring load applied through the tool 100, thereby reducing mechanical impact during the jarring process.
Moving now to FIGS. 10A(1)-A(2), FIGS. 10A(1)-A(2) present a new cross-sectional view of the milling tool 100 of the present invention. The cross-sectional view of FIGS. 10A(1)-A(2) show the milling tool 100 within the TRSSV 50 after the milling process has been completed. Compressive force is no longer being applied through the tool 100, and the tool 100 is beginning to be pulled from the wellbore. It can be seen in
Pulling up on the tool 100 causes a series of tension forces to be applied through the tool 100. The forces are as follows: from the thermal housing 120, to the motor housing 130, to the switch housing 140, to the bearing housing 150, to the setting mandrel 610, to the locating mandrel 660, to the cutter mandrel 630 through the ratchets 620, to the cutter mandrel head 670, to the cutter mandrel head shear pins 197. Continued upward force will ultimately shear the shear pins 197. In addition, continued upward force will pull the cutter body 480 and attached blades 218 and junk basket 700.
Finally, FIGS. 11A(1)-A(2) present a cross-sectional view of the milling apparatus 100 of
Of most importance in the view of
In order to conduct the milling operation of the present invention, a milling tool 100 is disposed at the end of a working string. The working string may be a slickline (including a wireline) or a string of coiled tubing or other string. The milling tool 100 is lowered into the production tubing of a well until it reaches the depth of a tubing-retrievable subsurface safety valve. The milling tool 100 is landed within the TRSSV, and is preferably landed on a shoulder within the bore of the valve for precise locating.
After landing, downward force is transmitted through the tool 100. Jarring down will shear the pins 662 to start the locking process. The locating mandrel 660 will shift down to push the locating logs 650 outward. If the locking dogs 640 are not located properly in the valve 50, the locating dogs 650 will constrain further action of the locking dogs 640 and will prevent the locking dogs 640 from setting. If the tool 100 is properly landed, then the locking dogs 640 will move outward into the profile 56 of the valve 50, or “landing nipple,” and over the OD of the locating mandrel 660, thereby permitting further action of the locking dogs 640.
As the locating mandrel 660 continues to move downward, the setting mandrel 610 OD will move out from underneath the cones 510, permitting their inward and downward movement until they contact the smaller OD of the setting mandrel 630. Further downward motion of the locating mandrel 660 causes the load ring 616 to contact the cones 510. The resulting downward motion of the cones 510 causes the buttons 520 to move radially outward and contact the ID of the safety valve 50. The cones 510 are constrained from moving radially outward by the ID of the button housing 170.
Further jarring down will compress the wave washers 802 to increase the load on the cones 510 and buttons 520. At maximum load, the locating mandrel 660 will bottom against the cutter mandrel head 670. Excessive jarring loads are taken up through the cutter head housing 210, the shear pin housing 190, the no-go body housing 180, and ultimately into the no-go shoulder of the valve housing 52, and do not transmit into the buttons 520. The wave washers 802 take up any backlash in the locking process (caused by ratchet motion, shear pin clearances, etc.) and maintain the maximum force on the buttons 520.
The jarring process also serves to initiate the actuation system 300. In this respect, after the milling tool 100 has been deployed in the TRSSV, the actuation system of the milling tool 100 is initiated. In one arrangement, actuation is begun by mechanically jarring down on the tool 100, causing the housing system 110 to telescopically compress. This, in turn, brings a magnetic force into sufficient proximity with a reed switch 330 in order to close an electrical circuit. Closure of the electrical circuit sends an enable signal from the reed switch 330 to initiate the startup sequence in the controller. After a specified delay, (e.g., 5-minutes by default), the controller 320 will ramp the motor 310 of the drive system 300 up to full speed, and maintain motor speed throughout the entire cut. The milling operation for the inner bore 55 of the primary valve 50 is then conducted.
The wave washer stack 802 applies force to the choke box 215 and choke pin 220. Together, the choke box 215 and choke pin 220 act as a cam follower to transmit the load of the wave washers 802 to the cam lobes 202 of the knives 218. A nearly constant knife tip load is maintained by the cam design.
During operation, the knives 218 will remove material from the chamber housing 52 of the valve 50. The resulting shavings are collected in the junk basket 702. The knives 218 will continue to remove material until communication has been established between the chamber housing ID and the chamber 57, at which time the knives 218 will reach their travel limit. Knife travel is limited by a shoulder that stops downward movement of the choke box 215 in the cutter body 480. The diametrical height of the knives 218 at this limit is set by the location of the choke pin 220 within the choke box 215.
The cutting process may take up to 15 or 20 minutes. When the reasonable time for milling has expired, hydraulic pressure may be applied into the hydraulic fluid line (not shown) into the TRSSV. A sudden drop in pressure indicates a successful communication. The motor 310 is optionally permitted to run until power is no longer supplied by the batteries 315. Continued milling will open the hole further and clean the cut. The batteries 315 should be completely depleted within an hour.
After completion of the cut, the cutter body 480 is pulled inside the cutter head housing 210 to retract the knives 218. The knives 218 spring out inside of a recess in the cutter head housing 210 and prevent the cutter body 480 from dropping back out for any reason. This is to ensure that the knives 218 stay retracted while pulling out of the hole. In addition, while pulling out, the junk basket 700 closes against the cutter head housing 210 to retain the metal chips that were trapped during the cut.
Pulling out of the hole will involve some upward jarring. Upward jarring is transmitted from the locating mandrel 660 to the cutter mandrel 630 through the ratchets 620, thereby shearing the steel shear pins 197 that lock the cutter mandrel head 670 into the shear pin housing 190.
Upward motion causes the larger OD of the setting mandrel 610 to strike the cones 510, moving them upward. This pulls the buttons 520 off of the valve's bore 55. At this point, the cutter mandrel 630, ratchet 620, and the entire locating system 600 moves upward until the locating dogs 650 strike the recess 56 of the valve housing 52. The cutting system 200 is then pulled into the cutting head housing 210, retracting the knives 218.
Still further upward motion pulls the locating mandrel 660 OD from under the locating dogs 650, thereby allowing the dogs 650 to retract. This frees the tool 100 from the primary valve 50 in the production tubing. Of course, upward jarring also causes the housing system 110 to telescope back out, moving the magnet 332 away from the switch 330. The circuit for the drive system 300 is thus opened. The controller 320 will immediately begin a shutdown sequence.
The present invention, therefore, is well adapted to carry out the above described objects and realize the advantages mentioned. Certain embodiments have been given for the purpose of disclosure, but variations to the details of construction, arrangement of parts and steps of the method may be afforded, and alternate uses of the present invention may be conceived without divergence from the scope and spirit of the present invention as described in the appended claims.
This application is a divisional of U.S. patent application Ser. No. 10/407,391, filed Apr. 4, 2003, now U.S. Pat. No. 7,188,674, which claims benefit of U.S. provisional patent application Ser. No. 60/408,366 filed on Sep. 5, 2002. Each of the aforementioned related patent applications is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60408366 | Sep 2002 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10407391 | Apr 2003 | US |
| Child | 11685595 | Mar 2007 | US |
