Patent Application
20150090446
The present disclosure relates generally to wellsite operations. In particular, the present disclosure relates to formation evaluation involving testing, sampling and/or analyzing downhole fluids.
Wellbores are drilled to locate and produce hydrocarbons. A downhole drilling tool with a bit at an end thereof is advanced into the ground to form a wellbore. As the drilling tool is advanced, drilling mud is pumped through the drilling tool and out the drill bit to cool the drilling tool and carry away cuttings. The fluid exits the drill bit and flows back up to the surface for recirculation through the drilling tool. The drilling mud is also used to form a mudcake to line the wellbore.
During a drilling operation, various downhole evaluations may be performed to determine characteristics of the wellbore and surrounding formations. In some cases, the drilling tool may be provided with devices to test and/or sample the surrounding formation and/or fluid contained in reservoirs therein. In some cases, the drilling tool may be removed and a downhole wireline tool may be deployed into the wellbore to test and/or sample the formation. These tests or samples may be used, for example, to determine whether valuable hydrocarbons are present.
Formation evaluation may involve drawing fluid from the formation into the downhole tool for testing and/or sampling. Various devices, such as probes or packers, may be extended from the downhole tool to establish fluid communication with the formation surrounding the wellbore and to draw fluid into the downhole tool. Downhole tools may be provided with fluid analyzers and/or sensors to measure downhole parameters, such as fluid properties. Examples of downhole devices are provided in U.S. Pat. Nos./Publication Nos. 8,397,817, 8,499,831, 7,703,526, 3,934,468, 3,782,191, 20040083805 and 20020189334, the entire contents of which are hereby incorporated by reference herein.
In at least one aspect, the disclosure relates to a probe of a downhole tool deployable into a wellbore penetrating a subterranean formation. The downhole tool has at least one flowline extendable therein. The formation has a clean fluid therein. The probe includes a base, a penetrating inlet, and an inlet packer. The base is carried by the downhole tool and positionable adjacent a wall of the wellbore. The penetrating inlet is carried by the base and has a tip about a sampling end thereof to receive the clean fluid. The penetrating inlet is in fluid communication with the at least one flowline, and is extendable through the wall of the wellbore a distance into the formation. The inlet packer is inflatably positionable about the penetrating inlet to form a seal with the formation and isolate the tip therein whereby the clean fluid may be drawn from the formation and into the downhole tool.
In another aspect, the disclosure relates to a downhole tool deployable into a wellbore penetrating a subterranean formation, the formation having a clean fluid therein. The downhole tool includes a housing having at least one flowline extending therein and a probe. The probe includes a base, a penetrating inlet, and an inlet packer. The base is carried by the housing and positionable adjacent a wall of the wellbore. The penetrating inlet is carried by the base and has a tip about a sampling end thereof to receive the clean fluid. The penetrating inlet is in fluid communication with the at least one flowline, and is extendable through the wall of the wellbore a distance into the formation. The inlet packer is inflatably positionable about the penetrating inlet to form a seal with the formation and isolate the tip therein whereby the clean fluid may be drawn from the formation and into the housing.
Finally, in another aspect, the disclosure relates to a method of sampling a downhole fluid of a subterranean formation. The formation has a wellbore extending therein, a clean fluid therein. The method involves deploying a downhole tool into the wellbore. The downhole tool includes a housing with at least one flowline extending therein and a probe. The probe includes a base carried by the housing, a penetrating inlet carried by the base and having a tip about a sampling end thereof, and an inlet packer positionable about the penetrating inlet. The penetrating inlet is in fluid communication with the flowline. The method also involves positioning the base adjacent a wall of the wellbore, selectively extending the penetrating inlet through the wall of the wellbore a distance into the subterranean formation, isolating the tip from contaminated fluid by inflating the inlet packer about the penetrating inlet and forming a seal with the formation, and drawing the clean fluid from the formation and into the housing through the tip.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
Embodiments of the method of formation evaluation are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components.
The description that follows includes exemplary apparatuses, methods, techniques, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.
The present disclosure relates to downhole tools used to sample downhole fluid. In particular, the disclosure describes a probe carried by a downhole tool and positionable in sealing engagement with a wall of a wellbore. The probe has a penetrating inlet with a tip at an end thereof extendable from the downhole tool, through the wellbore wall and into the surrounding formation. The tip may extend through the wall lined with mudcake, past an invaded zone containing contaminated fluid, and to clean fluid in the formation. The tip may also have a packer for forming a seal about the penetrating inlet. The packer may be positioned to isolate the tip from contaminated fluid to permit sampling of clean fluid.
The downhole drilling tool 10.1 may be withdrawn from the wellbore 14, and the downhole wireline tool 10.2 of
The downhole tools 10.1, 10.2 may be also provided with a formation evaluation tool 28 with a fluid collection and measurement means 30 for analyzing the formation fluid drawn into the downhole tools 10.1, 10.2. The formation evaluation tool 28 includes a flowline 32 for receiving the formation fluid from the probe 20 and passing the fluid to the fluid collection and measurement means 30 for analysis as will be described more fully herein.
The probe 20 may be extended from the downhole tools 10.1,10.2 for engagement with the wellbore wall 22. The probe 20 contacts the wellbore wall 22 and forms a seal with a mudcake 29 lining the wellbore wall 22. A mud filtrate of the mudcake 29 seeps into the wellbore wall 22 and creates an invaded zone 36 about the wellbore 14. The invaded zone 36 contains contaminated fluid including mud filtrate and other wellbore fluids that may contaminate surrounding formations, such as formation F, and a portion of clean formation fluid 38 in the formation F.
A surface unit 34 may be provided to communicate with the downhole tool 10.1, 10.2 for passage of signals (e.g., data, power, command, etc.) therebetween. Outputs may be generated from the surface unit 34 based on the measurements collected by the formation evaluation tool 28 and/or the fluid collection and measurement means 30. Such outputs may be in the form of data, measurements, reports, and/or other outputs.
While
Fluid drawn into the downhole tool through the probe 20 may be tested and/or sampled. The fluid may be tested using sensors S to measure various downhole parameters and/or fluid properties. The sensor(s) may include, for example, gauges (e.g., quartz), densitometers, viscometers, resistivity sensors, nuclear sensors, and/or other measurement and/or detection devices capable of taking downhole data relating to, for example, downhole conditions and/or fluid properties.
It may also be desirable and/or necessary to evaluate fluids at surface and/or offsite locations. In such cases, fluid samples may be collected in the downhole tool and taken to a surface and/or offsite location, and analyzed. Data and test results from various locations and/or using various methods and/or apparatuses may be analyzed and compared.
The probe 220 includes a base 236 and a penetrating inlet 242 extending from the base 236. The base 236 is operatively connectable to the downhole tool 210 by supports 240. The supports 240 may be movably positionable about the downhole tool 210 to selectively extend and retract the base 236. The supports 240 may have means, such as telescoping arms, selectively extendable from the downhole tool 210 using hydraulic, mechanical, electrical or other means. The probe 220 may be positioned on an exterior end of the supports 240 and selectively extendable thereby.
The base 236 is sealingly positionable adjacent the wall 22 of the wellbore 14. The base 236 may be sealable with a mudcake 29 lining the wellbore wall 22. The base 236 may have a sealing surface 244 to sealingly engage the wellbore wall 22 to fluidly isolate the penetrating inlet 242 from fluid in the wellbore 14. The sealing surface 244 may be, for example, a flexible or elastomeric member, such as a packer, sealingly engageable with the wellbore wall 22 and/or mudcake 29. The base 236 may be, for example, a metal plate carried by the supports 240 with a packer thereon positionable for engagement with the wellbore wall 22.
The penetrating inlet 242 may be a tubular member extending from the base 236. The penetrating inlet 242 may be perpendicular to the base 236 and extend laterally therefrom for insertion through the wall 22 of the wellbore 14. The penetrating inlet 242 may be positionable through the mudcake 29, the invaded zone 36 and into an uncontaminated portion of the formation F. The penetrating inlet 242 may be positionable a distance into the formation F to reach clean fluid 38 therein for testing and/or sampling.
As shown in
The probe 220 may also have an inlet connector 248 extending from the base 236 and to the downhole tool 210. The inlet connector 248 may fluidly couple the penetrating inlet 242 with the primary flowline 232 for fluid communication therebetween. The penetrating inlet 242 may be used to pass fluid from the formation F and into the primary flowline 232. The penetrating inlet 242 and/or the inlet connector 248 may be selectively extendable and retractable about the base 236 and/or downhole tool 210.
The penetrating inlet 242 and/or inlet connector 248 may be provided with, for example, drilling capabilities for forming a perforation and extending the penetrating inlet 242 into the formation. The drilling and extension of the tip 246, penetrating inlet 242 and/or inlet connector 248 may be provided by drilling means, such as a drilling tube 243 positioned about the penetrating inlet 242 and activatable to drill through the formation using a driver 245 (e.g., motor), or by separately drilling a perforation using a separate tool as provided, for example, in U.S. Pat. No. 7,703,526, previously incorporated by reference herein.
The primary flowline 232 may fluidly couple the probe 220 to the formation evaluation tool 228 for fluid communication therebetween. The formation evaluation tool 228 may receive the fluid for evaluation thereof. The formation evaluation tool 228 may have a variety of devices, such as a flow evaluation module 250, sample chamber 252, and/or other fluid collection and measurement means. The flow evaluation module 250 may have various measurement and/or analysis tools, such as sensors, gauges, fluid analyzers, and/or other devices for sensing, detecting, measuring, and/or determining various parameters of the downhole fluid.
The flow evaluation module 250 may also have a downhole unit 234 for receiving and/or processing data. The downhole unit 234 may be coupled to the surface unit 34 (
The fluid may be passed from the primary flowline 232a through the downhole tool 210 by a secondary flowline 254. The secondary flowline 254 fluidly connects the flow evaluation module 250 with the sample chamber 252. The fluid may optionally be discharged from the downhole tool 210 or collected in the sample chamber 252. The fluid collected in the sample chamber 252 may be maintained under pressure, and retrieved to the surface for further analysis.
Fluid may be drawn from the surrounding formation through the probe and into the downhole tool 210 via the primary flowline 232. The fluid may then be passed from the primary flowline 232 to the flow evaluation module 250, sample chamber 252, and/or other portions of the downhole tool via the secondary flowline 254. The downhole tool 210 and/or formation evaluation tool 228 may be provided with other flow control devices, such as pumps, valves, pretests, etc.
The penetrating inlet 342 includes a sampling intake 364 and a packer flow tube 366. The sampling intake 364 is a tubular member with a tip 346 at an end thereof. The packer flow tube 366 is concentrically positioned about the sampling intake 364. The tip 346 may extend a distance radially from the base 336 beyond the packer flow tube 366. Fluid may be drawn into the sampling intake 364 through the tip 346 as indicated by the arrows.
The sampling intake 364 may be coupled to the downhole tool 310 by an inlet connector 348. The inlet connector 348 may have a sampling connector 349a to provide fluid communication between the sampling intake 364 and a flowline 332 in the downhole tool 310 for the passage of fluid therebetween. Fluid sampled from the formation F may be passed into the sampling intake 364, through the inlet connector 348 and into the sampling flowline 332.
The packer flow tube 366 may have the inlet packer 360 thereabout. The inlet packer 360 may be a ring shaped member fluidly coupled to the packer flow tube 366 and expandable thereabout to fluidly isolate a portion of the perforation 362. The packer flow tube 366 may be coupled to the downhole tool 310 by a packer connector 349b of the inlet connector 348. The packer connector 349b may provide fluid communication between the packer flow tube 366 and a fluid source 368 as schematically depicted. The fluid source 368 may be selectively activated to inflate and deflate the inlet packer 360 as needed.
The inlet packer 360 extends radially about the packer flow tube 366 for sealing engagement with the perforation 362. As shown, the inlet packer 360 is positioned between a sampling end and a base end of the packer flow tube 366. The inlet packer 360 is positioned about the packer flow tube 366 between the invaded zone and the formation F to isolate a portion of the perforation 362. The inlet packer 360 may be used, for example, to prevent contaminated fluid from the wellbore and/or invaded zone from entering the sampling intake 364 or from contaminating the clean fluid 38 in the formation F.
The method may also involve collecting a sample of the downhole fluid, perforating the wall of the wellbore and deploying the penetrating inlet in the perforation, and/or retracting the penetrating inlet. The extending may involve selectively extending at least one of the tip and the penetrating inlet. The method may also involve performing a pretest, monitoring fluid properties, and measuring various downhole parameters. The method may be performed in a desired order and repeated in part or in whole as desired.
Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.
