Patent Application
20190368323
The present disclosure relates to tubing string rotator assemblies for rotating a tubing string within a hydrocarbon fluid well. The present disclosure also relates to safety rod clamp systems for use at the well tubing head or well casing head of a hydrocarbon well.
When producing fluids from hydrocarbon wells drilled into subterranean formations, a downhole pump is often placed deep within the well to pump the fluids in the formation to the surface. A tubing string extending from the bottom of the well to the surface is used as the conduit for the fluids to travel to the surface. Also, in some instances, a rotating rod or an up and down axially reciprocating pump rod may extend from the surface to the downhole pump through the interior of the tubing string. The pump rod can be rotated, or moved axially up and down, from the surface to transmit rotational power, or axially movement, to the pump at the bottom of the well, where it can be used to energize the pump.
The type and quantities of hydrocarbon fluids passing through the tubing string, as well as instances where the rotating pump rod comes into contact with the interior surface of the tubing string, can cause wear and erosion of the inner surface of the tubing string. In order to reduce, or at least more evenly distribute, this wear and erosion, it is known to rotate the tubing string suspended in a hydrocarbon well in an attempt to extend the life of the string. Typically, rotation devices, or rotators as they are commonly known, are bolted or otherwise attached to the well head of a hydrocarbon well and connected in some manner to the tubing string to cause the string to rotate. Rotators may use electrical or hydraulic power to cause the string to continuously rotate.
While such prior art rotators are effective at continuously rotating the tubing string, the rotation itself can cause wear at some contact points. For example, if the pump rod contacts the interior of the tubing string at a single point, rotation of the tubing string extends the wear around the entire inner circumference of the tubing string. If left unresolved, the wear around the inner circumference of the tubing string can ultimately cut the tubing string at the depth of the point of contact with the pump rod. There can be many similar wear points depending on the well geometry and the twisting of pump rods. As described, wear can negatively affect the integrity of the tubing string and fluid flow can be diverted from the tubing string.
In addition, rod clamps are used in the oil and gas industry to grip and hold the movement of polish rods during the servicing of the well. These clamps are used to hold the rod in tension and can, for example, sit at the top of the drive head or pumping unit. A polish rod, for example, is sealed with a stuffing box (mounted separately) that rotates with the rod or static seals. The rod clamp does not prevent the rods from coming out of hole if pressure or sand is exerted at the rotor. This can cause the entire working rod string to lift up the clamp with polish rod and become a whip posing a danger at the surface. Also, if the seal contact is lost with the polish rod, the stuffing box would lose pressure sealing. The action of the polish rod that comes out of well bore can damage equipment and operators. The industry standard is to lock the polish rod from moving when there is no rotation or axial movement, so the rod does not move with a locking seal rod blowout preventer (BOP).
In addition, tubing hangers are used to suspend a tubing string in a hydrocarbon well from a well casing head or a structure formed above the well casing head. Split tubing hangers generally support the weight of the tubing string, but do not prevent the tubing string from being raised out from the wellbore. The split tubing hanger includes a one-piece support mandrel that has a removable tubing outer sleeve that is connected and pinned in place. By removing the outer sleeve, the split tubing hanger thus allows the tubing string to be lowered below the well head to do service work, which typically requires rotating, circulating and reciprocating with the support mandrel portion of the tubing string.
Accordingly, there is a need to address one or more of the deficiencies of present tubing string rotators, safety rod clamps, and rotating split tubing hangers.
Tubing string rotators, safety rod clamps, combination tubing string rotators and safety rod clamps, and rotating split tubing hangers are provided. In some embodiments, the tubing string rotators are controllable such that they rotate the tubing string intermittently or non-continuously, which can cause even wear of the interior surface of the tubing string and extend its life.
Even wear of the interior surface of the tubing string is marked by the creation of longitudinally oriented “ribs” extending along the inner surface of the tubing, Formation of these “ribs”, through even erosion and wear, is desirable because they can increase the integrity of the tubing. Intermittent or non-continuous rotation of the tubing string can contribute to creating a desired “rib effect”.
According to one aspect, a tubing string rotator is provided for rotating a tubing string that is suspended in a hydrocarbon well by attachment to a rotatable support mandrel. The support mandrel can be positioned at the well casing head or well tubing head and can be supported against downward axial movement. The support mandrel can be rotatable with respect to the tubing head or well casing head such that rotation of the support mandrel causes rotation of the attached tubing string. The tubing string rotator comprises: a motor for producing a rotational force, a drive assembly for applying the rotational force to drive the rotation of the support mandrel, and a controller operatively connected to the motor for intermittently activating the motor, thereby causing rotation of the support mandrel, for selected intervals of time, followed by selected intervals of time of motor inactivation in which no rotation of the support mandrel occurs. The controller can also be used to selectively adjust the rate of rotation
In some embodiments, the motor can be an electric motor. In some embodiments, the motor can be a hydraulic motor.
In some embodiments, the support mandrel comprises a support mandrel upper end and a support mandrel lower end. The upper end of the tubing string is attachable to the support mandrel lower end, and the drive assembly can be operatively connected to the support mandrel upper end.
In some embodiments, the drive assembly comprises: a plugin mandrel comprising a plugin mandrel upper end and a plugin mandrel lower end, a gear mandrel, and a drive gear. The plugin mandrel lower end can be attachable to the support mandrel upper end such that rotation of the plugin mandrel causes rotation of the support mandrel, if attached. A person skilled in the art will realize that any connection between the plugin mandrel lower end the support mandrel upper end that can transmit rotation from the plugin mandrel to the support mandrel, and resist slippage, can be used. In some embodiments, the connection between the plugin mandrel lower end and the support mandrel upper end can be a splined connection. In some embodiments, the connection between the plugin mandrel lower end and the support mandrel upper end can be a mating hexagonal connection. In some embodiments, the connection between the plugin mandrel lower end and the support mandrel upper end can be a mating keyed connection.
A gear mandrel can be mounted on the plugin mandrel upper end such that rotation of the gear mandrel causes rotation of the plugin mandrel. In some embodiments, the gear mandrel can have a set of splines formed on its exterior that extend radially outward from the gear mandrel. The mounting of the gear mandrel on the plugin mandrel can be such that rotation of the gear mandrel causes rotation of the plugin mandrel.
A drive gear can be used to drive rotation of the gear mandrel. In some embodiments, the drive gear can be an elongate drive gear. The drive gear comprises: a first end operatively connected to the motor, and a second end forming a worm gear that can be engaged with the set of splines formed on the gear mandrel, such that the rotation force produced by the motor can be applied to drive rotation of the worm gear formed on the drive gear, causing rotation of the gear mandrel, the plugin mandrel, and the support mandrel, it provided.
In some embodiments, the controller can comprise a timer device. In some embodiments, the controller can be a variable speed drive system, a variable frequency drive system, an intermittent gear system, or a variation thereof.
According to another aspect, a safety rod clamp is provided for restraining a rod from bi-axial and/or rotational movement, the safety rod clamp comprising: at least two opposed ram assemblies for engaging the rod. Each of the ram assemblies comprising: a threaded ram shaft having a first end, a replaceable, threaded ram shaft insert fitted on the ram shaft, and a rod clamp member having a v-shaped surface. The threaded rod shaft inserts can be supported against any movement with respect to the well casing head or the well tubing head. Further, the rod shaft insert can be fitted on the ram shaft such that the threads of the ram shaft engage threads of the ram shaft insert and the position of the ram shaft with respect to the ram shaft insert can be selectively adjusted by rotation of the ram shaft. The first end of the ram shaft can be exposed when the rod shaft insert is fitted on the rod shaft and the rod clamp member can be positioned on the exposed first end of the ram shaft with the v-shaped surface facing away from the ram shaft. The v-shaped surface can engage the rod to restrain movement. In some embodiments, the rod can be can be restrained by equally rotating each of the ram shafts of the least two opposed ram assemblies towards the rod until the v-shaped surface frictionally engages the rod. The shape of the v-shaped surfaces on the rod clamp member are configured so the rod clamp members can frictionally engage pump rods or coil string tubing having many different diameters without having to change the rod champ members.
In some embodiments, the v-shaped surface further can comprise an engagement surface for frictionally engaging the rod.
In some embodiments, the rotation of the rod shafts can be a manual rotation. In some embodiments, the rotation of the rod shafts can be rotation using hydraulic power.
According to another aspect, a combination tubing string rotator and safety rod clamp is provided for use at a well head of a hydrocarbon well having a production rod extending through the well head and into the well. The combination comprising: an outer housing, a tubing string rotator, as described previously, and a safety rod clamp, as described previously. The production rod can extend through the outer housing. The tubing string rotator can be positioned within the outer housing such that the plugin mandrel extends out past a lower end of the outer housing for engagement with a support mandrel upper end. The safety rod clamp can also be positioned within the outer housing above the tubing string rotator such that the at least two ram assemblies can engage the pump rod or coil tubing, when moved into contact with the rod.
Embodiments of the present disclosure will now be described with reference to the accompanying Figures.
A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.
The term “invention” and the like mean “the one or more inventions disclosed in this application”, unless expressly specified otherwise.
The terms “an aspect”, “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, “certain embodiments”. “one embodiment”, “another embodiment” and the like mean “one or more (but not all) embodiments of the disclosed invention(s)”, unless expressly specified otherwise.
The term “variation” of an invention means an embodiment of the invention, unless expressly specified otherwise.
A reference to “another embodiment” or “another aspect” in describing an embodiment does not imply that the referenced embodiment is mutually exclusive with another embodiment (e.g., an embodiment described before the referenced embodiment), unless expressly specified otherwise.
The terms “including”, “comprising” and variations thereof mean “including but not limited to”, unless expressly specified otherwise.
The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise. The term “plurality” means “two or more”, unless expressly specified otherwise. The term “herein” means “in the present application, including anything which may be incorporated by reference”, unless expressly specified otherwise.
The term “e.g.” and like terms mean “for example”, and thus does not limit the term or phrase it explains.
The term “respective” and like terms mean “taken individually”. Thus if two or more things have “respective” characteristics, then each such thing has its own characteristic, and these characteristics can be different from each other but need not be. For example, the phrase “each of two machines has a respective function” means that the first such machine has a function and the second such machine has a function as well. The function of the first machine may or may not be the same as the function of the second machine.
Where two or more terms or phrases are synonymous (e.g., because of an explicit statement that the terms or phrases are synonymous), instances of one such term/phrase does not mean instances of another such term/phrase must have a different meaning. For example, where a statement renders the meaning of “including” to be synonymous with “including but not limited to”, the mere usage of the phrase “including but not limited to” does not mean that the term “including” means something other than “including but not limited to”.
Neither the Title (set forth at the beginning of the first page of the present application) nor the Abstract (set forth at the end of the present application) is to be taken as limiting in any way the scope of the disclosed invention(s). An Abstract has been included in this application merely because an Abstract of not more than 150 words is required under 37 C.F.R. Section 1.72(b) or similar law in other jurisdictions. The title of the present application and headings of sections provided in the present application are for convenience only, and are not to be taken as limiting the disclosure in any way.
Numerous embodiments are described in the present application, and are presented for illustrative purposes only. The described embodiments are not, and are not intended to be, limiting in any sense. The presently disclosed invention(s) are widely applicable to numerous embodiments, as is readily apparent from the disclosure. One of ordinary skill in the art will recognize that the disclosed invention(s) may be practiced with various modifications and alterations, such as structural and logical modifications. Although particular features of the disclosed invention(s) may be described with reference to one or more particular embodiments and/or drawings, it should be understood that such features are not limited to usage in the one or more particular embodiments or drawings with reference to which they are described, unless expressly specified otherwise.
Referring to
In some embodiments, the tubing string rotator assembly comprises a controller 55. As shown in
In some embodiments, controller 55 can be configured to automatically activate and deactivate the motor 20. By activating the motor 20, rotation of the support mandrel 40 can occur for desired or selected intervals of time, followed by selected intervals of motor inactivation in which no rotation of the support mandrel occurs. Therefore, controller 55 can create intermittent or non-continuous rotation of the support mandrel 40 and the tubing string, which can extend the wear life of the tubing string and keep the tubing string's structural integrity. Intermittent or non-continuous rotation of the tubing string may also contribute to even erosion and wear of the internal surface of the tubing string. Intermittent or non-continuous rotation of the tubing string may contribute to creating a desired “rib effect” on the inner surface of the tubing string. The controller 55 can also be used to control the rate or speed of rotation of the support mandrel 40.
Referring to
The support mandrel 40 can be part of a rotating split tubing hanger 61. Also part of the rotating split tubing hanger 61, an outer sleeve 44 is mounted to the support mandrel 40 and a housing sleeve 52. Positioned between support mandrel 40 and the outer sleeve 44 is housing sleeve 52 that can be configured to allow the support mandrel 40 rotate within the outer sleeve 44, while still allowing outer sleeve 44 to be removable relative to the support mandrel 40 and the housing sleeve 52.
As will be discussed further below, outer sleeve 44 can have a support surface 53 that acts as a load bearing shoulder and extends radially outward relative to housing sleeve 52 and support mandrel 40. Support surface 53 can be sized to engage the well casing head 70, as shown in
The tubing string rotator assembly 20 can be used to rotate the tubing string so that erosion and wear of the string is evenly distributed about its inner surface. The tubing string can be rotated by rotating the support mandrel 40 to which it is attached.
In some embodiments, motor 20 can be an electric motor that uses electricity to produce the rotational force to drive rotation of the support mandrel 40. In some embodiments, motor 20 can be a hydraulic motor that uses hydraulic power to produce the rotation force that drives rotation of the support mandrel 40.
As is shown in
Referring now to
In some embodiments, a shear collar 24 can be included in drive assembly 54 with pins that are adjustable to the working torque in order to prevent over torqueing of the tubing rotator 20 to the tubing string. In some embodiments, the shear collar can be a ratcheting shear collar safety device.
In some embodiments, controller 55 can comprise a timer device, which can be used to activate and deactivate the motor 20 for desired or selected intervals of time. In some embodiments, controller 55 can be a variable speed drive, a variable frequency drive, or an intermittent gear assembly.
Referring to
Referring still to
In some embodiments, the v-shaped engagement surface 36 can be ribbed for frictional engagement with the production rod 60. The v-shaped engagement surface 36 can be configured to fit and be engagable with a variety of production rods 60 having different sized diameters for frictional engagement that will restrain relative movement. This can decrease service time required when a different sized production rod 60 is used at the location of the well. In some embodiments, the rod clamp member 33 can be fitted with a resilient sealing member (not shown) that at least partially covers the v-shaped surface 36 for sealing the engagement of the v-shaped surface 36 with the production rod, in addition to clamping the rod. Similar to the clamping described above, the resilient sealing member is configured to seal the engagement, for example from well fluids, of the v-shaped engagement surface 36 with production rods having a variety of diameters. Also, the internal dimension, for example, the flow path through the safety clamp, can, in some embodiments, be sealed using the resilient sealing member.
Removable threaded shaft inserts 31 can be used for many kinds of threaded applications where the threads can be damaged and an insert is replaceable on location instead with a thread on the part. This can cut the operational cost when a threaded main body is damaged and a service is required without pulling the assembly or shutting the operation to repair the damage. The removable ram assembly can be replaced if the thread is damaged on the removable threaded shaft insert 31 with a new insert. This allows the main body 58 to not be removed if the threads get damaged but shut down only for the service time. This assembly can work for any moving shafts that have a threaded part to move engaging parts.
Referring to
Changes can be made to the present tubing string rotator assemblies, safety rod clamps, and combinations of a tubing string rotator and a safety rod clamp in light of the above description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the invention is not limited by the disclosure, but instead its scope is to be determined entirely by the following claims.
This application claims the benefit of U.S. Provisional Application No. 62/452,194, filed Jan. 30, 2017, the disclosure of which is incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2018/050107 | 1/30/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62452194 | Jan 2017 | US |
