Abstract: A method for accessing a subterranean zone includes forming a subterranean cavity coupled to a land surface and forming a plurality of substantially horizontal bores extending at least partially into the subterranean zone and intersecting the cavity.

Abstract: In accordance with the teachings of the present invention, a method is provided for preventing formation of sludge in a subsurface cavity having particulate laden fluid disposed therein. The method includes positioning a downhole device having a fluid agitator into the fluid of the subsurface cavity and agitating the fluid using the fluid agitator.

Abstract: A method and system for enhancing permeability of a subterranean zone at a horizontal well bore includes determining a drilling profile for the horizontal well bore. At least one characteristic of the drilling profile is selected to aid in stabilizing the horizontal well bore during drilling. A liner is inserted into the horizontal well bore. The well bore is collapsed to increase permeability of the subterranean zone at the horizontal well bore.

Abstract: A well bore liner is carried on a working string into a main bore of a well. A well bore liner is directed from the main bore into an auxiliary bore of the well with a whipstock. The whipstock is coupled to a working string without withdrawing the working string from the main bore. The whipstock is then relocated in the well using the working string.

Abstract: A method for underground treatment of subsurface materials comprises providing an injection pattern and a recovery pattern, the injection pattern and the recovery pattern located proximate to a subsurface treatment zone and at least one of the injection pattern and the recovery pattern comprising a plurality of lateral bores extending from a main bore. A treatment solution is injected through the injection pattern and recovered through the recovery pattern.

Abstract: A subterranean zone can be accessed from the surface by forming a well bore extending from the surface into the subterranean zone. A tubing string is provided within the well bore, and an underreamer passed over the tubing string to a specified location within the subterranean zone. The underreamer is operated in forming an enlarged cavity in the well bore, and the subterranean zone about the tubing string is collapsed. Pressure within the enlarged cavity my be reduced to facilitate collapse of the subterranean zone about the tubing. The tubing string is provided with apertures, either before being positioned in the well or after, to allow passage of fluids into an interior of the tubing string. The fluids from the subterranean zone may be withdrawn through the tubing string.

Abstract: A method for extracting accumulated material from a well bore includes pressurizing gas recovered from the well bore and disposing an extraction string in communication with a sump. The sump is disposed to receive liquid from the well bore. The method further includes sealing the sump and injecting at least a portion of the pressurized gas into the sump such that at least some of the liquid in the sump is driven upward into the extraction string.

Abstract: A system for lining a junction between a main bore and an auxiliary bore includes a first tubing adapted to line at least a portion of the main bore. The first tubing has a lateral opening therein. A second tubing has a junction shield extending outward therefrom. The junction shield has a larger transverse dimension than the lateral opening and is adapted to contract to a smaller transverse dimension to pass through the lateral opening into the auxiliary bore.

Abstract: A method for accessing a subterranean zone from the surface includes drilling a substantially vertical well bore from the surface to the subterranean zone and forming a slot cavity in the substantially vertical well bore proximate to the subterranean zone. The slot cavity comprises a substantially non-cylindrical shape. The method also includes drilling an articulated well bore from the surface to the subterranean zone. The articulated well bore is horizontally offset from the substantially vertical well bore at the surface and intersects the substantially vertical well bore at a junction proximate to the subterranean zone. The method may include drilling the articulated well bore to intersect the slot cavity of the substantially vertical well bore and drilling a substantially horizontal drainage pattern from the slot cavity into the subterranean zone. The subterranean zone may comprise a coal seam.

Abstract: A device for perforating a tubing string residing in a well bore includes a tubular housing adapted to pass through the tubing string. At least one perforating body is provided residing in the housing, and has a point adapted to pierce the tubing string. A piston is received within the housing, the piston configured such that pressure applied to a first side of the piston causes the piston to move in a first direction. An actuator body is received within the housing and configured for movement in the first direction with the piston. The actuator body has a sloped wedge surface adapted to wedge the at least one perforating body radially outward to pierce the tubing string with the point when the actuator body is moved in the first direction.

Abstract: A system for accessing a subterranean zone from an entry well including an entry well extending from the surface. The entry well has a substantially vertical portion. A one or more drainage wells extend from the entry well to a subterranean zone. A one or more articulated wells extend from the entry well to the subterranean zone. At least one of the articulated wells intersects at least one of the one or more drainage wells at a junction proximate the subterranean zone. A drainage pattern is formed coupled to the junction and operable to conduct fluids from the subterranean zone to the junction.

Abstract: In accordance with the teachings of the present invention, a method is provided for preventing formation of sludge in a subsurface cavity having particulate laden fluid disposed therein. The method includes positioning a downhole device having a fluid agitator into the fluid of the subsurface cavity and agitating the fluid using the fluid agitator.

Abstract: In accordance with one embodiment of the present invention, a method for lining a lateral wellbore includes drilling a main wellbore extending from a surface to a subterranean zone, casing the main wellbore with a main casing having a plurality of lateral wellbore windows formed therein, positioning a whipstock having a longitudinal bore running therethrough adjacent a respective one of the lateral wellbore windows, forming a lateral wellbore through the respective lateral wellbore window using the whipstock, lining the first lateral wellbore with a lateral liner and a portion of a tie-back assembly that has a pre-milled lateral wellbore window formed therein, aligning the pre-milled lateral wellbore window with the longitudinal bore, and coupling the tie-back assembly to the main casing.

Abstract: A method and system for testing a partially formed well includes forming a first well bore intersecting a subterranean formation. The first well bore includes a portion of a planned well having a first configuration. A production characteristic of the subterranean formation is tested through the first well bore in the first configuration. The first well bore is reconfigured to a second configuration different from the first configuration. The production characteristic of the subterranean formation is re-tested through the first well bore in the second configuration. Further formation of the planned well is planned based on testing of the subterranean formation through the first well bore in the first and second configurations.

Abstract: An underreamer for forming a cavity within a well bore includes a fluid motor having a first body and a second body arranged about a longitudinal axis. The first body is adapted to rotate about the longitudinal axis in relation to the second body when fluid is passed between the first and second bodies. The fluid motor further defines a longitudinal tubing passage adapted to allow passage of the fluid motor over a tubing string. At least one cutting arm is coupled to rotate with the first body, and radially extendable into engagement with an interior of the well bore to form the cavity.

Abstract: According to one embodiment of the invention, a system for directional drilling within a wellbore includes a drill string having an upper portion, a lower portion, a bent motor coupled to the lower portion, and a drill bit coupled to bent motor, and a clutch assembly disposed between the upper and lower portions. The clutch assembly is operable to disengage the upper and lower portions of the drill string and allow the upper portion to rotate while the lower portion does not rotate.

Abstract: According to one embodiment of the invention, a downhole separation method includes forming a main wellbore extending from a surface to a subterranean zone, disposing a production liner into the main wellbore proximate the subterranean zone, coupling a first end of a first tube to the production liner, coupling an entrance portion of a second tube to an outside surface of and adjacent a second end of the first tube such that an entrance of the second tube is at a lower elevation than the second end of the first tube, and causing a flow of a mixture through the production liner and the first tube. The mixture includes a gas, a liquid, and a plurality of coal fines. The method further includes retrieving the gas via the main wellbore after the mixture exits the second end of the first tube and retrieving at least the liquid through the second tube.

Abstract: A method for stimulating production of resources from a coal seam includes forming a drainage well bore in the coal bed that has a first end coupled to a ground surface and a second end in the coal seam. The method further includes inserting a liner into the well bore. The liner has a wall including a number of apertures and a second diameter that is smaller than the first diameter of the drainage well bore such that a gap is formed between the wall of the liner and the well bore. The method also includes collapsing the drainage well bore around the liner to relieve stress in the coal seam proximate to the liner.

Abstract: A method for recirculating fluid in a well system includes drilling a first well bore from a surface to a subterranean zone, and drilling an articulated well bore that is horizontally offset from the first well bore at the surface and that intersects the first well bore at a junction proximate the subterranean zone. The method also includes drilling a drainage bore from the junction into the subterranean zone, and receiving gas, water and particles produced from the subterranean zone at the junction via the drainage bore. The gas, water, and particles are received from the junction at the surface, and the water is separated from the gas and the particles. The method also includes determining an amount of water to circulate, and recirculating a portion of the separated water according to this determination.

Abstract: A well system includes at least two well bores extending from a surface to a subterranean zone. Each of the two well bores is used to form a well bore pattern for the subterranean zone that intersects the other well bore and transports fluid from the subterranean zone to the other well bore for production to the surface. In addition, each of the two well bores is operable to collect fluids transported to the well bore by the well bore pattern formed through the other well bore for production to the surface.