Patent Application
20210285296
The present disclosure relates generally to downhole drilling tools, and specifically to an energized ring valve for use therein.
When drilling a hydrocarbon production well, it may be desirable to maintain a specific drilling direction. For this reason, steerable systems may be utilized to control the direction of propagation of the wellbore. Typical steerable systems may include a rotating section that includes the drill bit and any associated shafts, and a non-rotating section that remains substantially non-rotating relative to the surrounding formation.
Steerable drilling systems are often classified as either “point-the-bit” or “push-the-bit” systems. In point-the-bit systems, the rotational axis of the drill bit is deviated from the longitudinal axis of the drill string in the direction of the wellbore. The wellbore may be propagated in accordance with a three-point geometry defined by upper and lower points of contact between the drill string and the wellbore, defined as touch points, and the drill bit. The angle of deviation of the drill bit axis, coupled with the distance between the drill bit and the lower touch point, results in a non-collinear condition that generates a curved wellbore as the drill bit progresses through the formation.
Some embodiments of a steering tool for use in a wellbore may comprise a tool housing coupled to and positioned about a tubular mandrel having a bore therethrough, the tool housing able to rotate about the mandrel; a steering cylinder formed in the housing, wherein the steering cylinder may be fluidly coupled to a first steering port and contains fluid at a steering cylinder pressure; a steering blade coupled to the housing, the steering blade at least partially positioned within the steering cylinder, the steering blade extendable by an extension force to contact a wellbore, wherein the extension force may be caused by a differential pressure between the steering cylinder pressure and a fluid pressure in the wellbore; and a ring valve. The ring valve may include a gear housing; a manifold mechanically coupled to the tool housing, a valve seat, a valve carrier mechanically coupled to the valve seat and having upper and lower valve carrier surfaces, an upper valve housing mechanically coupled to the gear housing; a lower valve housing mechanically coupled to the upper valve housing and reciprocably coupled to the valve carrier; and at least one biasing means positioned between the valve carrier and the lower valve housing and configured to urge the valve carrier away from the lower valve housing.
The manifold may include an upper manifold surface having at least one manifold orifice therein. The manifold orifice may provide fluid communication between the upper manifold surface and the first steering port and may fluidly couple the bore to the steering cylinder. The valve seat may have a lower ring surface positioned in abutment with the upper manifold surface. The valve seat may be rotatable relative to the manifold and the lower ring surface may be configured such that rotation of the valve seat relative to the manifold selectively opens and closes the at least one manifold orifice. The lower valve carrier surface may circumferentially support the valve seat.
The valve carrier may have an upper valve carrier surface and the lower valve housing may have a biasing surface configured to bear on the upper valve carrier surface. The biasing surface may include at least two receptacles that are each configured to receive a biasing means. The biasing surface may include at least sixteen receptacles and the tool may include twelve biasing means each partially received in a receptacle and positioned between the valve carrier and the lower valve housing. The tool further may include four containment pins each partially received in a receptacle and positioned between the valve carrier and the lower valve housing. The receptacles may be evenly spaced about the circumference of the steering tool. Each biasing means may be selected from the group consisting of: coil springs, Belleville washers, elastomeric members, and leaf or bow springs. The steering tool may further include a seal, an O-ring, a snap ring, and a thrust bearing between the lower valve housing and the upper valve housing.
In some embodiments a method for drilling a well may comprise the steps of: a) providing a drill string that includes a downhole steering tool, b) using the downhole steering tool to steer while drilling, and c) using the pressure sensor to measure pressure in the steering port and using the measured pressure to adjust operation of the downhole steering tool.
The downhole steering tool may comprise a housing coupled to and positioned about a tubular mandrel, the housing able to rotate about the mandrel, the housing having a plurality of steering cylinders formed therein, each steering cylinder fluidly coupled to a respective steering port; a plurality of steering blades coupled to the housing, each steering blade at least partially disposed within a respective steering cylinder, each steering blade extendable by a differential pressure between a respective steering cylinder pressure and a pressure in the wellbore surrounding the downhole tool, the differential pressure caused by fluid pressure in a respective steering port; a pressure sensor in at least one steering port; and a ring valve, the ring valve including a gear housing and a manifold mechanically coupled to the tool housing. The manifold may include an upper manifold surface having at least one manifold orifice therein and the manifold orifice may provide fluid communication between the upper manifold surface and steering port so as to fluidly couple the bore to the steering cylinder.
The ring valve may further include a valve seat, the valve seat having a lower ring surface positioned in abutment with the upper manifold surface. The valve seat may be rotatable relative to the manifold and the lower ring surface may be configured such that rotation of the valve seat relative to the manifold selectively opens and closes at least one manifold orifice. The ring valve may further include a valve carrier mechanically coupled to the valve seat and having upper and lower valve carrier surfaces. The lower valve carrier surface may circumferentially support the valve seat. The ring valve may further include an upper valve housing mechanically coupled to the gear housing and a lower valve housing mechanically coupled to the upper valve housing and reciprocably coupled to the valve carrier.
The ring valve may further include at least one biasing means positioned between the valve carrier and the lower valve housing and configured to urge the valve carrier away from the lower valve housing.
In some embodiments, the downhole steering tool may include a pressure sensor in each steering port and the method may include the steps of d) using the ring valve to cause extension of the steering blades by controlling pressure in each steering port; and e) using the pressure measured in step c) as feedback to control the extension of the steering blades in step d). Additionally or alternatively, the method may include the steps of d) using the ring valve to generate pressure pulse shapes for mud-pulse telemetry and e) using the pressure data measured in step c) as feedback to control the generation of pressure pulses in step d). Additionally or alternatively, the method may include the step of d) using the pressure data measured in step c) to sense mud pulses arriving at the downhole tool. Additionally or alternatively, the method may include the step of d) using the pressure data measured in step c) to detect or diagnose a malfunction in the ring valve.
The downhole steering tool may include a pressure sensor in each steering port and the method may further include using the pressure measured in step c) to execute at least two of: i) a steering feedback step comprising ia) using the ring valve to cause extension of the steering blades by controlling pressure in each steering port and ib) using the pressure measured in step c) as feedback to control the extension of the steering blades in step ia); ii) a signaling feedback step comprising iia) using the ring valve to generate pressure pulse shapes for mud-pulse telemetry; and iib) using the pressure data measured in step c) as feedback to control the generation of pressure pulses in step iia); iii) a sensing step comprising using the pressure data measured in step c) to sense mud pulses arriving at the downhole tool; and iv) a diagnostic step comprising using the pressure data measured in step c) to detect or diagnose a malfunction in the ring valve.
Each of steps i), ii), iii) and iv) may be carried out at least once during a single drilling operation. Step ib) may comprise adjusting the position of the valve seat relative to the manifold so as to adjust a fluid flow through at least one manifold orifice. Step iib) may comprise changing the valve movement velocity. Step iv) may trigger a jam mitigation step in which the ring valve opens and closes at least one manifold orifice.
The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
As depicted in
Downhole steering tool 100 may include a housing 101. In some embodiments, housing 101 may be tubular or generally tubular. Housing 101 may be positioned about mandrel 12 and may be rotatably coupled thereto such that mandrel 12 may rotate independently of housing 101. In some embodiments, for example and without limitation, one or more bearings may be positioned between housing 101 and mandrel 12. Although shown as a single piece, one having ordinary skill in the art with the benefit of this disclosure will understand that housing 101 may be formed from one or more pieces.
In some embodiments, housing 101 may rotate at a speed that is less than the rotation rate of the drill bit 14 and mandrel 12. In some embodiments, housing 101 may rotate at a speed that is less than the rotation speed of mandrel 12. For example and without limitation, housing 101 may rotate at a speed at least 50 RPM slower than mandrel 12. For example and without limitation, in an instance where mandrel 12 rotates at 51 RPM, housing 101 may rotate at 1 RPM or less. In some embodiments, housing 101 may be substantially non-rotating, and may rotate at a speed that is less than a percentage of the rotation speed of mandrel 12. For example and without limitation, housing 101 may rotate at a speed lower than 50% of the speed of mandrel 12. In some embodiments, housing 101, by not rotating substantially, may maintain a toolface orientation independent of rotation of drill string 10.
In some embodiments, downhole steering tool 100 may include one or more steering blades 103. Steering blades 103 may be positioned about a periphery of housing 101. Steering blades 103 may be radially extendible to contact wellbore 15. In some embodiments, steering blades 103 may be at least partially positioned within corresponding steering cylinders 105 and may be sealed thereto. Steering cylinders 105 may be formed in housing 101. Steering cylinders 105 may, in some embodiments, be cavities formed in housing 101 into which steering blades 103 are at least partially positioned such that fluid may flow into steering cylinders 105 and apply fluid pressure to steering blades 103. Fluid pressure within each steering cylinder 105, defining a steering cylinder pressure, may increase above fluid pressure in the surrounding wellbore 15, defining a wellbore pressure, thereby causing a differential pressure across the steering blade 103 positioned therein. The differential pressure may exert an extension force on steering blade 103. The extension force on steering blade 103 may urge steering blade 103 into an extended position. When positioned within wellbore 15, the extension force may cause steering blade 103 to contact the wall of wellbore 15. In some embodiments, steering blade 103 may, for example and without limitation, at least partially prevent or retard rotation of housing 101 to, for example and without limitation, less than 20 revolutions per hour.
In some embodiments, fluid may be supplied to each steering cylinder 105 through a steering port 107 formed in housing 101. The fluid in each steering port 107 may be controlled by one or more adjustable orifices 109. Fluids may include, but are not limited to, drilling mud, such as oil-based drilling mud or water-based drilling mud, air, mist, foam, water, oil, including gear oil, hydraulic fluid or other fluids within wellbore 15. Adjustable orifices 109 may control fluid flow between an interior of mandrel 12 and steering ports 107. In some embodiments, each steering cylinder 105 is controlled by an adjustable orifice 109. In some embodiments, one or more steering blades 103 may be aligned about downhole steering tool 100 and may be controlled by the same adjustable orifice 109. As used herein, “adjustable orifice” includes any valve or mechanism having an adjustable flow rate or restriction to flow.
Fluid may be supplied to each adjustable orifice 109 from bore 13 of mandrel 12. Adjustable orifices 109 may be in fluid communication with bore 13 of mandrel 12. In some embodiments, for example and without limitation, one or more apertures 111 may be formed in mandrel 12 and fluidly coupled to each adjustable orifice 109, thereby allowing fluid to flow to each adjustable orifice 109 as mandrel 12 rotates relative to housing 101. In some embodiments, as further discussed herein below, a diverter may be utilized.
In some embodiments, adjustable orifices 109 may be reconfigurable between an open position and a partially open position. In some embodiments, adjustable orifices 109 may further have a closed position. In the partially open position, the amount of fluid that may pass through an adjustable orifice 109 into the corresponding steering cylinder 105 is less than the amount that may pass through in the fully open position. During certain operations, for instance to centralize downhole steering tool 100 within wellbore 15, as depicted schematically and without limitation as to structure in
When a steering input is desired, one or more adjustable orifices (depicted as adjustable orifice 109a′ in
In some embodiments, when drilling a straight or nearly straight wellbore 15, all adjustable orifices 109a-d may be opened, applying substantially equal pressure to all steering blades 103, causing equal force exerted by all steering blades 103 against wellbore 15. Alternatively, a gripping force may be exerted by all steering blades 103 against wellbore 15 when all adjustable orifices 109a-d are partially open.
In some embodiments, as depicted in
Referring again to
Referring still to
Pressure data sensors may be installed to measure fluid pressure at various points in the system and environment. Pressure data sensors may comprise transducers or any other device capable of measuring pressure. By way of example only and without limitation, the following fluid pressures may be measured: the annular pressure, internal pressure, ring valve pressure, manifold fluid pressure, compensation fluid pressure, or pad piston pressure. Pad piston pressure may be measured by pressure sensors positioned in one or more of the steering ports 107 and is indicative of the force applied to the respective steering blades 103. In embodiments where pad piston pressure is to be measured, pressure sensors may be positioned so as to measure the fluid pressure in one or more steering ports 107 or adjacent to one or more orifices 109. (such as for three, four, or more pads), etc. By way of example only, suitable miniature pressure data recorders are described in US. Pat. App. 20180066513 “Drilling Dynamics Data Recorder,” which includes the pressure transducer and various drilling dynamics sensors. Optionally, these pressure recorders may be connected to the rotary-steerable-system's main controller via communication bus and the main controller may be able to utilize the pressure data to better control the toolface (steering direction) and steer force (dogleg).
The ring valve system has a position sensor and in normal operation, the adjustable orifice positions can be precisely controlled. Due to various circumstances, however, the pressure that is actually applied at each pad face may deviate from the intended pressure. Deviation may be the result of, for example, position sensor drift, misalignment of valve components, or debris in one or more fluid passages, With the aid of pressure transducers installed, for example, in each pad piston, the pad pressures may be fine-regulated to control the toolface and the dogleg, thereby improving control of the wellbore trajectory. The force is the pressure multiplied by the cross-section area of the piston. In this case the cross-section area is constant; therefore, the force is substantially proportional to the pressure applied.
In addition, pressure transducer data from each pad may optionally be used by the RSS main controller/processor to detect or diagnose a valve jam and/or piston jam event. In such cases, the processor may be programmed to perform a pre-programmed jam mitigation algorithm, such as closing the all the orifices and sequentially or simultaneously opening the orifices. By way of example, if a leaky valve is detected, i.e. the valve is closed, but there is still piston pressure, the valve can go through pre-programmed sequences to try to eliminate the cause of the problem. For example, the valve could go shift through each orifice open/closed position.
Another application of pad pressure information is in ring valve telemetry. Optionally, pressure transducer data may be transmitted to the surface via shorthop and MWD mud pulse telemetry. The pressure transducer data may be used as feedback on the generation of intended pressure waveforms, such as sinewave pressure pulses. Control based on the pressure transducer data can be accomplished by adjusting the valve movement velocity based on the measured differential pressure between the valve top and piston pressures. The valve movement velocity can be changed by regulating the electrical motor speed.
In order to generate desired mud pressure changes for signaling, the ring valve may be moved from an all-closed position to an all-open position in which all four pads are activated. The all-closed position generates the highest pressure values (upward telemetry) and the all-open position generates the lowest pressure values. By monitoring the valve top pressure or, alternatively all pad/piston pressures, the valve movement velocity may be precisely controlled to generate an intended mud-pulse waveform.
Optionally, pressure transducer data may be transmitted to the surface via shorthop and MWD mud pulse telemetry. The transmitted pressure data may be used to optimize the operation of the RSS and/or diagnostics of the tool, such as calculating equivalent circulating density, identifying drilling fluid loss, detecting bit nozzle malfunction, etc.
RSS commands or other information may be transmitted from the surface. Optionally, the pressure transducers may be used to detect such flow-rate and/or fluid-pressure modulation downlinks from the surface. For example, the flow rate may be manually changed at the surface based on the coded sequences to give a downlink command or to send a data point to the RSS. In some embodiments, pad pressure data may comprise the received signal; in other embodiments, it may be used in conjunction with one or more second sensors elsewhere in the tool, so as to increase accuracy of a received signal.
Thus, pad pressure data can be used to support various feedback, diagnostic, and sensing steps. By way of example, pad pressure data may be used in a steering feedback step comprising using the ring valve to cause extension of the steering blades by controlling pressure in each steering port and using the pad pressure data as feedback to control the extension of the steering blades. By way of another example, pad pressure data may be used in a signaling feedback step comprising using the ring valve to generate pressure pulse shapes for mud-pulse telemetry and using the pad pressure data as feedback to control the generation of the pressure pulses. By way of another example, pad pressure data may be used a sensing step comprising using the pad pressure data to sense mud pulses arriving at the downhole tool. By way of another example, pad pressure data may be used in a diagnostic step comprising using the pressure data to detect or diagnose a malfunction in the ring valve.
Referring briefly to
Referring now to
As best illustrated in
It may be desirable to maintain alignment and a tight clearance between upper valve housing 180 and gear housing 190. In some embodiments, the components may be bolted together. In addition, it may be desirable to transfer load from lower valve housing 170 to upper valve housing 180 via thrust bearing 188.
Referring now to
In some embodiments, lower valve housing 170 may include a lower surface, hereinafter referred to as biasing surface 170a. A timing pin 164 may mechanically engage both valve carrier 160 and lower valve housing 170. Timing pin 164 may be substantially longitudinal. Lower end 164a of timing pin 164 may be received in and/or affixed substantially permanently to valve carrier 160. The opposite end, upper end 164b, of timing pin 164 may be slidably received in a corresponding receptacle 174 in biasing surface 170a of lower valve housing 170. Receptacle 174 may be sized such that some longitudinal movement of timing pin 164 is possible. In these embodiments, valve carrier 160 can move longitudinally with respect to lower valve housing 170 but is prevented from rotating or moving laterally relative thereto.
Also as shown in
Referring now to
Referring now to
Receptacles 177 and 179 in lower valve housing 170 may be identical, and each may be capable of receiving either a containment pin 166 or a biasing means 168. In some embodiments, there may be a plurality of containment pins 166 and biasing means 168; in the illustrated embodiment, lower valve housing 170 includes sixteen receptacles evenly spaced about biasing surface 170a and four containment pins 166 and twelve biasing means 168 are received therein. The number and relative proportion of containment pins 166 and biasing means 168 can be varied as desired and is limited only by the number of receptacles provided. In embodiments having more than one biasing means 168, the biasing means may be evenly spaced about the circumference of the tool. Containment pins 166 ensure that the center line of the ring valve is always aligned with the centerline of the manifold. In addition, containment pins 166 ensures that the ring valve surface and the manifold surface are parallel. The biasing means 168 maintains contact between these two surfaces.
Together, containment pins 166 and biasing means 168 provide a balanced and distributed force urging valve carrier 160 away from lower valve housing 170. The force on valve carrier 160 ensures that fluid channels through ring valve assembly 215 will remain closed when desired. One advantage of the energized valve is that when it is operated at a pressure drop less than the desired pressure drop (e.g. 400 psi, instead of the recommended 600 psi), the valve still activates the proper pad(s)/blade(s). The present device ensures that the valve is pressed against the manifold surface, avoiding unintended or undesirable pad activation. The present device also provides consistent operation even when inclined or influenced by downhole dynamics; the valve remains pressed against the manifold, ensuring the proper activation of the desired pad(s).
Because of the movement allowed between valve carrier 160 and lower valve housing 170, lower valve housing 170, second seal 182, O-ring 184, snap ring 186, thrust bearing 188, and upper valve housing 180 can be securely coupled and sealed together and that tolerances between upper valve housing 180 and gear housing 190 can be tightened. By way of example, the components can be machined to fit and/or shimmed to fit.
Referring briefly to
When the tool is fully assembled, lower ring surface 151 may abut upper manifold surface 219 such that when a slot 152 is aligned with one or more orifices of a manifold orifice set 221, fluid can flow through the aligned orifices from a fluid supply port 106 coupled to the interior of mandrel 12 as previously discussed. In some embodiments, slots 152 may be arranged such that valve seat 150 needs only rotate a partial turn to actuate adjustable orifices 109. In some embodiments, slots 152 may be arranged about valve seat 150 such that adjustable orifices 109 opposite one another are not open at the same time. In some embodiments, slots 152 may be arranged such that adjacent adjustable orifices 109 may be opened at the same time. Thus, ring valve assembly 215 may be used to control the flow of any fluid that flows through mandrel 12.
Ring valve assembly 215 may be actuated by a motor and pinion, which engage the back of gear housing 190, indicated generally at 241. The motor and pinion may be controlled by a controller (not shown) so as to move slots 152 into and out of alignment with manifold orifice sets 221. In some embodiments, valve seat 150 may be rotatable by one or more full revolutions. The controller may include, for example and without limitation, one or more microcontrollers, microprocessors, DSP (digital signal processing) chips, FPGAs (field programmable gate arrays), a combination of analog devices, such analog integrated circuits (ICs), or any other devices known in the art, which may be programmed with motor controller logic and algorithms, including angular position controller logic and algorithms.
As the ring valve assembly 215 is actuated in and out of its various open positions, biasing means 168 applies a constant and distributed load to valve carrier 160 and thereby serves to maintain contact between valve seat 150, which is seated on valve carrier 160, and manifold 217. This in turn maintains the desired fluid flow path through the tool.
In some embodiments, downhole steering tool 100 may transmit data to the surface. In some embodiments, for example and without limitation, a series of pressure pulses may be utilized to transmit communication signals. The pressure pulses may be generated by the opening and closing of one or more steering ports 107 by ring valve assembly 215.
In some embodiments, the pressure pulses may be utilized to transmit a binary signal. In some embodiments, Manchester encoding may be utilized to transmit data to the surface, including but not limited to inclination, azimuth, housing gravity/magnetic toolface, target toolface, actual toolface, housing rotation speed, bit rotation speed, shock/vibration severities, stick-slip severities, high-frequency-torsional-oscillation (HFTO) severities, temperatures, pressure, other diagnostic information, and so on. An advantage of the present device is that it makes the pressure pulse signal magnitude consistent and reliable by maintaining the desired fluid flow path through the tool.
The foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure. Such features may be replaced by any one of numerous equivalent alternatives, only some of which are disclosed herein. One of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. One of ordinary skill in the art will also understand that such equivalent constructions do not depart from the scope of the present disclosure and that they may make various changes, substitutions, and alterations to the devices disclosed herein without departing from the scope of the present disclosure.
