Abstract: A method and apparatus for drilling a lateral from a primary wellbore having a short radius-of-curvature. The lateral is drilled by a downhole drilling unit which differs from prior art units of this type in that instead of connecting the drill bit directly to the downhole motor, a length of flexible drill pipe is used to connect the bit to the rotary power output of the motor. This length of flexible drill pipe below the downhole motor allows much larger build-up angles (e.g. 1-3° per foot) which, in turn, reduces the time and expense for short-radius laterals and increase the accuracy of placement of the lateral within the zone of interest (e.g. production formation).

Abstract: A downhole assembly for setting a well tool (e.g. packer) comprising a setting tool which has a draw rod made in two portions which are slidably connected to allow relative movement therebetween. The upper portion is releasably latched to the well tool wherein the weight of the well tool is effectively supported by the workstring rather than the draw rod during positioning of the assembly. Upon actuation of the setting tool, the upper portion is released from the well tool thereby allowing movement between the portions to switch the weight of the well tool to the draw rod during the setting of the well tool. By effectively unloading the draw rod during positioning of the assembly, the assembly can be retrieved if necessary without inadvertently setting the well tool or shearing the draw rod.

Abstract: A method and a toolstring for carrying out a downhole operation in a wellbore (e.g. milling a window in a well casing, drilling a lateral wellbore, etc.). The toolstring is comprised of a workstring and a downhole assembly which is comprised of a downhole, rotary motor (e.g. bent motor) for driving a cutting tool (e.g. carbide mill, drill bit, etc.) and a valve which is movable between a first position in which the flow of work fluid is blocked to the motor and a second position in which the fluid is now directed to the motor to thereby actuate the motor and drive the cutting tool. By initially blocking flow of fluid to the motor, certain functions can be performed within the wellbore (e.g. orienting the bent motor) before the motor begins any cutting within the wellbore.

Abstract: A method and system for increasing oil production from an oil well producing a mixture of oil and gas at an elevated pressure through a wellbore penetrating an oil-bearing formation containing an oil-bearing zone and an injection zone, by separating at least a portion of the gas from the mixture of oil and gas to produce a separated gas and an oil-enriched mixture; utilizing energy from at least a portion of the mixture of oil and gas to compress at a surface at least a portion of the separated gas to produce a compressed gas having sufficient pressure to be injected into the injection zone; injecting the compressed gas into the injection zone; and recovering at least a major portion of the oil-enriched mixture.

Abstract: An apparatus for milling a window in a well tubular, e.g. a well casing, which is comprised of a whipstock and a cooperating mill. The mill has a nose portion depending from the bottom thereof and has cutting surfaces on both the bottom and the sides. The whipstock is comprised of a body which, in turn, has a tapered surface along at least a portion of its length. A guide, e.g. cylindrical pipe, is mounted on and is spaced from the tapered surface and is adapted to receive the nose portion on the mill to provide a guide path for the mill as it cuts or mills a window in the well casing. The guide is positioned so as to direct the side cutting surface of the mill into contact with the casing without contacting the tapered surface of the whipstock.

Abstract: A system and a method for producing increased quantities of oil from an oil well producing a mixture of oil and gas through a well bore penetrating an oil bearing formation containing a gas cap zone and an oil bearing zone by separating at least a portion of the gas from the mixture of oil and gas downhole in an auger separator to produce a separated gas and an oil enriched mixture; compressing at least a portion of the separated gas downhole to a pressure greater than the pressure in the gas cap zone to produce a compressed gas; and, injecting the compressed gas into the gas cap and, recovering at least a major portion of the oil enriched mixture.

Abstract: A mill starting device for use in a pipestring in a wellbore which provides an inclined wall for guiding the mill to a shoulder stop so that when the mill is operated it preferentially bites into the shoulder stop and a method for using the device together with coiled tubing for forming a window in a subsurface well conduit.

Abstract: A well conduit cutting and milling apparatus conveyable into and out of a well on coilable tubing using a tubing injection unit. The apparatus includes tubing or casing cutting arms which are radially extendable and retractable with respect to a cylindrical support body by pressure fluid operated pistons. The apparatus is made up of multiple end-to-end connected units including one which supports interchangeable cutting and milling arms and units which have radially extensible and retractable stabilizing arms which engage the inner wall of the tubing or casing to centralize and stabilize the apparatus during operation. The cutter and milling arms are modified for milling away a section of tubing by moving the apparatus in an upward or out of the well direction. The cutting elements are preferably cylindrical hard metal members which are supported on the arms for cutting away an end face of the tubing in a tangential direction of movement.

Abstract: Coring and other operations may be carried out through a cased wellbore by placing a permanent whipstock having a tool guide surface thereon in the wellbore through the production tubing string and anchoring the whipstock with cement after positioning the whipstock in a predetermined orientation of the guide surface. An underreamer faces off the cement and cuts a pilot bore for guiding a casing cutting tool so that the whipstock guide surface is properly engaged during the casing wall milling and core drilling operations. The whipstock is inserted into the wellbore through a production tubing includes a hydraulic actuator for moving the whipstock laterally after exiting the lower end of the tubing string to assist in supporting the whipstock in the wellbore and to properly orient the guide surface. The actuator is supplied with pressure fluid through a coilable tubing string connected to the whipstock during the insertion and placement process.

Abstract: The lower end of a wellbore tubing string or a change in diameter of a wellbore component may be sensed by an apparatus connectable to the end of an elongated coilable tubing for insertion into the tubing string and responsive to movement of the apparatus into or out of the end of the tubing string to effect a change in flow of fluid being conducted through the coilable tubing. The apparatus includes opposed arms engageable with the bore of the tubing string and engageable with a piston member to effect closure of ports in the apparatus to change the flow of fluid through the tubing in response to movement of the arms into or out of the end of the tubing string. Alternate embodiments include bypass passages for conducting pressure fluid to a packer or wellbore tool.

Abstract: Connectors for connecting coilable tubing and other relatively thin walled tubing strings to downhole tools are provided which are releasable to permit withdrawal of the tubing without a member connected to the tubing that is substantially larger in diameter than the tubing itself. One embodiment of the connector includes a body member having plural collet fingers which are engagable with the tubing distal end through cooperating circumferential grooves and lands. The collet fingers are retained in gripping engagement with the tubing by a retainer sleeve having a piston head which catches a pump down ball to block a flow passage in the retainer and allow a fluid pressure force to shear plural shear screws which hold the retainer in the finger engaging position. Alternate embodiments includes recesses formed in the wall of the tubing for receiving ball keys which are held in registration with the recesses by the connector body and a cooperating slidable sleeve member.

Abstract: A downhole tool carries an inflatable packer by means of which radial pressure may be applied to the surrounding formation. Transducers within the packer measure the radial direction and extent of formation displacements responsive to such pressure. In this way one can determine the directions of maximum and minimum horizontal in-situ formation stress.

Abstract: Medium curvature deviated wellbores having a radius of curvature in the range of 200 feet to 400 feet are drilled with downhole drilling assemblies for drilling the curved wellbore portion and for correcting or holding the horizontal wellbore portion and which are connected to the end of a drillstem made up of elongated elastically bendable drillstem members which may be cyclically compressively stressed during rotation of the drillstem. The elastically bendable drillstem members are characterized by joint forming portions at opposite ends of an elongated tubular body and which are of a diameter which minimizes the tendency for the drillstem to buckle during drilling. Spaced apart stress bearing sleeves are attached to or integrally formed with the tubular body and are of a diameter greater than the body and preferably equal to the diameter of the tool joint portions.

Abstract: Sand is evacuated from horizontal and vertical wellbores utilizing a jet pump connected to the distal end of a concentric tubing string which is insertable in the wellbore and extendable from the earth's surface or from a seal member providing a crossover flow path between the wellbore annulus above the seal member and the inner tubing member of the concentric tubing string. The jet pump includes a plurality of nozzles for ejecting evacuation of fluid into the wellbore to agitate and entrain accumulated solids for flow into a pump inlet cavity and to be propelled out of the pump by a portion of the evacuation fluid acting as a jet pump power fluid. The inner tubing member may be coilable tubing which is inserted into the outer tubing member after the jet pump has been lowered into the wellbore. An upper portion of the concentric tubing string may be made up of preassembled sections of the inner and outer tubing members.

Abstract: A means for substantially reducing the bending stresses, both tensional and compressional, in a standard-type length of drill pipe as it passes through a section of a wellbore that is deviated from vertical. The tool joints on the ends of drill pipe have outside diameters greater than that of the pipe body which act as supports for the pipe body against the wall of the wellbore in a deviated section. The bending stresses encountered by the drill pipe increase as the distance between these pipe supports increase. In the present invention, stress sleeves are affixed to the outer surface of the pipe body at equally spaced intervals between the tool joints to act as dummy tool joints thereby providing additional pipe supports which substantially reduce the bending stresses in the drill pipe.

Abstract: In deep drainhole drilling, a specially oriented drill collar of generally elliptic cross section is combined with a drill bit, a downhole motor and means adapted to deflect the bit to drill the build section of the drainhole curving at a medium angle of 2.degree. to 50.degree. per hundred feet. Preferably, the drill collar is at least twenty feet long. The elliptic drill collar is oriented in a manner such that the minor axis of the ellipse lies generally in the direction of the intended curve of the build interval. For the desired vertical build, this places the locus of the minimum axis of the ellipse toward the vertical and the locus of major axis toward the horizontal when the curved interval of the drainhole approaches horizontal. Preferably, the minor axis is at least twenty percent shorter than the major axis.

Abstract: A method and apparatus for cutting a series of patterns spaced along the length of a tubular member (e.g. drill collar). A cutting torch is positioned and manuevered within the bore of the pipe so that all cutting is done in an inside-to-outside direction. All slag formed by the cutting action is blown away from the pipe and does not collect within the pipe bore as in previous cutting operations of this type. Further, since there is no cross-wash of the torch, there is no substantially no heat buildup in the pipe during cutting which allows proper preheating of the pipe thereby alleviating cold cuts in the pattern.

Abstract: A method and apparatus for drilling and/or working in a drainhole wellbore which extends laterally from a primary wellbore which utilizes flexible hose which can be deployed into the primary wellbore and recovered from the primary wellbore in a coiled fashion, and uses apparatus for coiling, deploying and recovering the flexible hose which includes a rotatable drum operatively connected with a movable beam and guide means. The beam and guide means are utilized to position the flexible hose over the primary wellbore in such a manner that essentially only vertical external forces and essentially no lateral external forces are applied to the apparatus thereby eliminating the need to rigidly fix the apparatus to the earth or other support means when in use.