Patent Application
20130175050
The present disclosure relates generally to downhole drilling operations and, more particularly, to stabilizing downhole tools from lateral vibration and borehole contact.
Typical subterranean drilling apparatuses include stabilizers with stabilizer blades that contact the borehole wall and prevent lateral movement of the drilling apparatus within the borehole. Unfortunately, the stabilizer blades can become caught or lodged in the borehole wall, causing the drill string to “stick”. When the drilling apparatus “sticks”, the rotational movement of the drill string is either stopped or severely decreased. Torque is still imparted to the drill string at the surface, despite the stabilizer being stuck, causing the drill string to twist. Once the torque applied to the drill string overcomes the force of friction on the stabilizer blades, the drill string “slips” or releases from the borehole wall. This configuration is problematic because it decreases the lifespan of downhole components, it decreases the quality of the borehole, and it requires large amounts of torque to “slip” the drill string.
A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.
The present disclosure relates generally to downhole drilling operations and, more particularly, to stabilizing downhole tools from lateral vibration and borehole contact.
Illustrative embodiments of the present invention are described in detail below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of the present disclosure.
To facilitate a better understanding of the present disclosure, the following examples of certain embodiments are given. In no way should the following examples be read to limit, or define, the scope of the disclosure. Embodiments of the present disclosure may be applicable to horizontal, vertical, deviated, multilateral, u-tube connection, intersection, bypass, or otherwise nonlinear wellbores in any type of subterranean formation. Embodiments may be applicable to injection wells, and production wells, including natural resource production wells such as hydrogen sulfide, hydrocarbons or geothermal wells; as well as borehole construction for river crossing tunneling and other such tunneling boreholes for near surface construction purposes or borehole u-tube pipelines used for the transportation of fluids such as hydrocarbons. Embodiments described below with respect to one implementation are not intended to be limiting.
Modern petroleum drilling and production operations demand information relating to parameters and conditions downhole. Several methods exist for downhole information collection, including logging while drilling (“LWD”) and measurement-while drilling (“MWD”). In LWD, data is typically collected during the drilling process, thereby avoiding any need to remove the drilling assembly to insert a wireline logging tool. LWD consequently allows the driller to make accurate real-time modifications or corrections to optimize performance while minimizing down time. MWD is the term for measuring conditions downhole concerning the movement and location of the drilling assembly while the drilling continues. LWD concentrates more on formation parameter measurement. While distinctions between MWD and LWD may exist, the terms MWD and LWD often are used interchangeably. For the purposes of this disclosure, the term LWD will be used with the understanding that this term encompasses both the collection of formation parameters and the collection of information relating to the movement and position of the drilling assembly.
The stabilizer 108 in the BHA 107 may contact the borehole wall and prevent lateral movement of the BHA 107 within the borehole 108. Typical stabilizers may comprise fixed blades that can become caught or lodged in the borehole wall 105, causing the drill string 106 to “stick”. When the drill string “sticks”, the rotational movement of the drill string 106 is either stopped or severely decreased. Torque may still be imparted to the drill string 106 from the rig 101, despite the stabilizer 108 being stuck, causing the drill string 109 to twist. Once the torque overcomes the force of friction on the stabilizer 108, the drill string 106 may “slip” or release from the borehole wall 105. This “slip” and “stick” action may decrease the lifespan of downhole components, including LWD/MWD measurement elements 109 and 110, and decrease the quality of the borehole 105.
In certain embodiments, the SSR 200 may be included within a BHA using one or both of the box and pin connections 203 and 204. The SSR 200 may also be included within a drill string apart from the BHA. Additionally, as would be appreciated by one of ordinary skill in view of this disclosure, the SSR 200 may be included within a BHA or drill string with other connections mechanisms known in the art.
The SSR 200 may comprise a first roller 205 disposed on an outer surface of the cylindrical tool body 201 at a first location 206. The SSR 200 may also comprise a second roller 207 disposed on the outer surface of the cylindrical tool body 201 at a second location 208. The second location 208 may be offset from the first location 206 both laterally and circumferentially with respect to a longitudinal axis 209 of the cylindrical tool body 201. The rollers 205 and 207 may comprise elongated structures parallel to the longitudinal axis 209 of the cylindrical tool body 201. Other roller embodiments are possible, including but not limited to spherical rollers.
In certain embodiments, the SSR 200 may comprise a third roller 210 disposed on the outer surface of the cylindrical tool body 201 at a third location 211. The third location 211 may be offset from the first location 206 and the second location 208 both laterally and circumferentially with respect to a longitudinal axis 209 of the cylindrical tool body 201. Although SSR 200 includes three rollers at three different lateral and circumferential locations, this configuration is not meant to be limiting. For example, certain embodiments may include less than three rollers or more than three rolles, each offset laterally and circumferentially. Likewise, certain embodiments may include less than three roller or more than three rollers, with only some of the rollers offset laterally and circumferentially. Other variations would be appreciated by one of ordinary skill in the art in view of this disclosure.
In certain embodiments, the SSR 200 may include a first cavity 212 within the cylindrical tool body 201, in which the first roller 205 may be partially disposed. The SSR 200 may also include a second cavity 213, in which the second roller 207 may be partially disposed. The first cavity 212 and second cavity 213 may be located at the first location 206 and second location 208, respectively. In certain embodiments, the SSR may also include a third cavity 214 corresponding to the third location 211, in which the third roller 210 is partially disposed.
To accommodate communications and drilling fluid flow through the SSR 200, a feedthrough may be disposed within the internal bore 202.
In certain embodiments, the thickness of the cylindrical tool body 201 of the SSR 200 may be increased, allowing the depth of the cavities to be increased to accommodate larger rollers. Notably, if the slim feedthrough 300 is used, the thickness of the cylindrical tool body 201 of the SSR 200 may be increased without large sacrifices in flow area through internal bore 202. With the thickness of the cylindrical tool body 201 increased, the SSR 200 may accommodate rollers with a larger diameter, which are typically used for larger boreholes. In certain embodiments, for example, the SSR 200 may be sized to accommodate rollers typically used in a 9 7/8 inch borehole, even though the SSR 200 may be intended for use in an 8 1/2 inch borehole. In certain other embodiments, the rollers may comprise XDrilling Tools WedgeTail™ roller technology, which provide for longer bearing life. More robust and larger rollers, such as 9 7/8 inch XDrilling Tools WedgeTail™ may reduce the maintenance costs of the SSR 200.
As will be appreciated by one of ordinary skill in the art in view of this disclosure, the SSR 200 with slim feedthrough 300 may replace a typical stabilizer with blades, and eliminate the wall contact of the stabilizer blades, which cause sticking The staggered rollers of the SSR 200 may allow the drill string to rotate freely without the additional torque necessary to “slip” the drill string. The SSR 200 may also dampen MWD/LWD sensors from damaging lateral vibration, as the rollers of the SSR 200 may contact the borehole wall, preventing such vibration. Moreover, with the rollers staggered laterally on the face of the SSR 200, both the interior flow area of the SSR 200 and the exterior flow area between the SSR 200 and the borehole may be preserved. Additionally, the staggered placement may also provide a larger contact area between the SSR 100 and the borehole wall, allowing for better stabilization, prevention of lateral vibration, and prevention of wall contact by adjacent MWD/LWD tools and sensors.
According to aspects of the present disclosure, an example method for reducing stick-slip in drilling operations may comprise coupling a downhole tool to a drill string. The downhole tool may comprise a cylindrical tool body, a first roller disposed on an outer surface of the cylindrical tool body at a first location, and a second roller disposed on the outer surface of the cylindrical tool body at a second location. The second location may be offset laterally and circumferentially from the first location on the cylindrical body. The method may further include positioning the downhole tool within a borehole.
According to aspects of the present disclosure, an example method for manufacturing a downhole tool for reducing stick-slip in drilling operations may comprise providing a cylindrical tool body. The method may also comprise positioning a first roller on an outer surface of the cylindrical tool body at a first location, and positioning a second roller on the outer surface of the cylindrical tool body at a second location. The second location may be offset laterally and circumferentially from the first location on the cylindrical tool body. In certain embodiments, the cylindrical tool body may comprise a first cavity and a second cavity, and positioning the first and second rollers may comprise disposing the first roller and second roller within the first and second cavities respectively.
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. The indefinite articles “a” or “an,” as used in the claims, are each defined herein to mean one or more than one of the element that it introduces.
The present application claims priority to U.S. Provisional Application No. 61/583,468, filed on Jan. 5, 2012, entitled “Method and Apparatus for Reducing Stick Slip in Drilling Operations”, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61583468 | Jan 2012 | US |
