Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: A departure device couples to a bit using a connector that facilitates release of the bit from the departure device. The connector may be more millable than the departure device and can transmit axial and torque loads between the bit and the departure device. The connector may include a material having lesser strength or hardness than the departure device, and may be millable by the bit. Another example connector may have connection points with the bit, and a movable member of the departure device may a force to the connector and contribute to releasing the connection between the bit and the departure device. A tensile connector between the bit and the movable member may apply a tension force to the movable member, urging the movable member toward an extended position in which the movable member is aligned coherently with a sloped face of the departure device.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: A cutting apparatus and method to facilitate milling of a casing window by improving the interaction between the mill and the casing. The cutting apparatus comprises a whipstock having a plurality of ramp sections that provide a ramp profile arranged and designed to cooperate with the cutting structure of a mill to achieve a desired loading on the mill cutting elements during milling of the casing window. The plurality of ramp sections, having specific lengths and oriented at specific angles, adjust the loading on the mill as the mill cuts through the casing during formation of the casing window. The improved whipstock maintains a more balanced loading across the cutting elements during milling operations. Additional mill cutting structures may also be selected and evaluated to further balance the cutting load during window milling.

Abstract: A departure device couples to a bit using a connector that facilitates release of the bit from the departure device. The connector may be more millable than the departure device and can transmit axial and torque loads between the bit and the departure device. The connector may include a material having lesser strength or hardness than the departure device, and may be millable by the bit. Another example connector may have connection points with the bit, and a movable member of the departure device may a force to the connector and contribute to releasing the connection between the bit and the departure device. A tensile connector between the bit and the movable member may apply a tension force to the movable member, urging the movable member toward an extended position in which the movable member is aligned coherently with a sloped face of the departure device.

Abstract: A cutting element for use with a bit may include an obtuse cutting edge. The cutting edge may be formed between a cutting face and a slanted face of the cutting element. The obtuse cutting edge may be pre-formed in the cutting element for use with a bit used to mill a window in casing and/or drill a deviated borehole. The cutting element may be positioned on the bit as a trailing cutting element, and oriented to cause the obtuse cutting edge to engage casing and/or a rock formation.

Abstract: Systems facilitate forming lateral wellbores by optionally eliminating one or more trips downhole. The systems provide for forming a lateral wellbore by enabling the milling of a casing window and/or the drilling of the desired lateral wellbore to a target depth during a single trip down hole. The systems also facilitate improved downhole dynamics control and overall bottom hole assembly functionality.

Abstract: A steerable drill bit may be used to drill a lateral borehole from a primary wellbore. The steerable drill bit may be part of a bottomhole assembly that also includes a directional control system. A deflection member, such as a whipstock, may be anchored in the primary wellbore. When the bottomhole assembly approaches the deflection member, the directional control system may steer the steerable drill bit to reduce and potentially eliminate contact between the steerable drill bit and a ramped surface of the deflection member. By restricting contact between the deflection member and the steerable drill bit, cutting elements of the steerable drill bit may obtain an increase in cutting efficiency and/or effective life.

Abstract: A coring system and method enable a single-trip operation for setting a deflector assembly, deploying a coring assembly and obtaining a core sample from a borehole drilled in a wellbore. The coring assembly has a barrel with a bore for collecting the core sample and has a coring bit coupled to an end portion of the barrel. The deflector system is arranged to deflect the coring bit into a side wall of the wellbore to drill the borehole therein. The deflector system includes a deflector and a collar. The collar, coupled to the deflector, restricts upward movement of the coring assembly relative to the deflector assembly. The collar may also be used as a retrieval device to engage the coring assembly and permit removal of the coring assembly and the deflector assembly as well as the core sample after the core sample has been obtained.

Abstract: A system and method for facilitating the drilling of a deviated borehole. The system and method employ a flexible conveyance. A hydraulic actuation assembly is coupled to the flexible conveyance and a whipstock is releasably coupled to the hydraulic actuation assembly. The whipstock and hydraulic actuation assembly are conveyed downhole in the wellbore. The hydraulic actuation assembly provides a hydraulic fluid under pressure to anchor the whipstock.

Abstract: A cutting element for use with a bit may include an obtuse cutting edge. The cutting edge may be formed between a cutting face and a slanted face of the cutting element. The obtuse cutting edge may be pre-formed in the cutting element for use with a bit used to mill a window in casing and/or drill a deviated borehole. The cutting element may be positioned on the bit as a trailing cutting element, and oriented to cause the obtuse cutting edge to engage casing and/or a rock formation.

Abstract: A cutting apparatus and method to facilitate milling of a casing window by improving the interaction between the mill and the casing. The cutting apparatus comprises a whipstock having a plurality of ramp sections that provide a ramp profile arranged and designed to cooperate with the cutting structure of a mill to achieve a desired loading on the mill cutting elements during milling of the casing window. The plurality of ramp sections, having specific lengths and oriented at specific angles, adjust the loading on the mill as the mill cuts through the casing during formation of the casing window. The improved whipstock maintains a more balanced loading across the cutting elements during milling operations. Additional mill cutting structures may also be selected and evaluated to further balance the cutting load during window milling.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: Milling systems, tools, and methods include using a mill with a barrier to promote re-circulation of debris and cuttings to the face of the mill. The face of the mill may include cutting elements. A barrier may obstruct the flow of cuttings and debris away from the face to re-circulate the cutting and debris to promote re-milling of the cuttings and debris by the cutting elements of the face of the mill. The barrier may include a hydraulic barrier formed by fluid expelled from nozzles in or above the mill. A secondary attrition system uphole of the mill may also be used to stage conditioning and re-sizing of cuttings and debris. After debris and cuttings pass through the barrier, the secondary attrition system may re-mill the cuttings and debris to a finer size before allowing the cuttings and debris to pass into the wellbore annulus for transport to the surface.

Abstract: A cutting apparatus and method to facilitate milling of a casing window by improving the interaction between the mill and the casing. The cutting apparatus comprises a whipstock having a plurality of ramp sections which provide a ramp profile arranged and designed to cooperate with the cutting structure of a mill to achieve a desired loading on the mill cutting elements during milling of the casing window. The plurality of ramp sections, having specific lengths and oriented at specific angles, adjust the loading on the mill as the mill cuts through the casing during formation of the casing window. The improved whipstock maintains a more balanced loading across the cutting elements during milling operations. Additional mill cutting structures may also be selected and evaluated to further balance the cutting load during window milling.

Abstract: A system and method facilitate sidetracking by eliminating one or more trips downhole. A sidetracking system includes a whipstock assembly and a stinger assembly. The stinger assembly has a stinger which extends at least partially through the whipstock assembly. The stinger is coupled to a sub of the sidetracking system by a releasable latch mechanism, such as a shear pin or collet.

Abstract: Systems facilitate forming lateral wellbores by optionally eliminating one or more trips downhole. The systems provide for forming a lateral wellbore by enabling the milling of a casing window and/or the drilling of the desired lateral wellbore to a target depth during a single trip down hole. The systems also facilitate improved downhole dynamics control and overall bottom hole assembly functionality.

Abstract: A retrieval tool may include a body having a first end portion and a second end portion. A protrusion may extend laterally from the body proximate the second end portion of the body. The protrusion may have an engaging surface, two opposing side surfaces, and an outer surface. A path of fluid communication may extend from the first end portion of the body, through the body and the protrusion, to an engaging surface of the protrusion. A method for moving a downhole tool in a wellbore may include running a retrieval tool into a wellbore and pumping fluid to the retrieval tool. The retrieval tool may be engaged with the downhole tool, which may cause a path of fluid communication to experience a change in fluid pressure.

Abstract: A system and method facilitate drilling of lateral wellbores by optionally eliminating one or more trips downhole. The system and method provide for drilling a lateral wellbore by enabling the milling of a casing window and the drilling of the desired lateral wellbore to a target depth during a single trip down hole. The system and method also facilitate better downhole dynamics control and improved overall bottom hole assembly functionality during drilling.