Abstract: A method for designing a core bit to control and reduce the cutting forces acting on a core of rock is disclosed. The method includes generating a model of a core bit including a plurality of cutting elements on a plurality of blades. The method may additionally include simulating a coring operation with the model of the core bit. The method may further include calculating at least one force vector generated by at least one of the plurality of cutting elements on the model of the core bit during the coring operation. The method may further include determining at least one force acting on a core in the model of the core bit based on the at least one force vector and generating a design of the core bit based on the at least one force acting on the core.

Abstract: Methods, devices, and systems include a nested drill bit assembly, including an inner drill bit nested within an opening of an outer drill bit. The inner drill bit is removably coupled to the outer drill bit and the inner drill bit being co-axially positioned within the outer drill bit and accessible from a first end of the outer drill bit.

Abstract: A system for obtaining a core sample from a wellbore includes a housing having a core opening at a first end of the housing and an end wall at a second end of the housing. A balancing piston is positioned within the housing to define a sample chamber between the balancing piston and the core opening. An equalization chamber is defined between the balancing piston and the end wall. A core piston is sealingly positioned in the core opening.

Abstract: Disclosed are systems and methods of coupling plain end pipes. One system includes a coupling sleeve having opposing upper and lower ends and a plurality of axially extending slots defined in each end, wherein the upper end is configured to receive an end of a first pipe and the lower end is configured to receive an end of a second pipe, an upper sliding ring disposed about the coupling sleeve and axially movable in a first direction to force the upper end into gripping engagement with an outer surface of the first pipe, and a lower sliding ring disposed about the coupling sleeve and axially movable in a second direction to force the lower end into gripping engagement with an outer surface of the second pipe.

Abstract: Methods, devices, and systems include a nested drill bit assembly, including an inner drill bit nested within an opening of an outer drill bit. The inner drill bit is removably coupled to the outer drill bit and the inner drill bit being co-axially positioned within the outer drill bit and accessible from a first end of the outer drill bit.

Abstract: A method for obtaining a core sample from a wellbore using a coring tool is disclosed. The method includes providing an outer barrel in the wellbore. The wellbore and outer barrel are at least partially filled with a drilling fluid. The method further includes lowering an inner barrel partially into the drilling fluid and displacing the drilling fluid in the inner barrel with a coring fluid.

Abstract: There is disclosed herein drilling apparatus, in particular for use in the field of oil prospecting, comprising: a first tubular member (1, 2, 3); a second tubular member (6, 7, 8, 9) mounted at least partly within the first tubular member so as to be reciprocally free in rotation with respect to the first tubular member about an axis (5); and a drill bit (4) operatively connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling, characterized in that: the drilling apparatus further comprises a restoring member (18, 36) for applying a forces between the first tubular member and the second tubular member at least in respective first axial directions in response to relative displacement of the first tubular member and the second tubular member in the respective opposite axial directions. Also provided are a tubular assembly and a method of assembling tubular members.

Abstract: A method for designing a core bit to control and reduce the cutting forces acting on a core of rock is disclosed. The method includes generating a model of a core bit including a plurality of cutting elements on a plurality of blades. The method may additionally include simulating a coring operation with the model of the core bit. The method may further include calculating at least one force vector generated by at least one of the plurality of cutting elements on the model of the core bit during the coring operation. The method may further include determining at least one force acting on a core in the model of the core bit based on the at least one force vector and generating a design of the core bit based on the at least one force acting on the core.

Abstract: An example system for receiving gas expelled from a core sample of a formation may include a tubular element. A core chamber may be disposed within the first tubular element. A gas and drilling fluid separator may be in fluid communication with the core chamber. The tubular element may be an inner barrel assembly of a core sample assembly that is disposed within a borehole. A core sample may be contained within the inner barrel assembly and may be retrieved at the surface. Gas may be expelled from the core sample as it is retrieved, and the gas and drilling fluid separator may separate the expelled gas from suspension with a drilling fluid for analysis.

Abstract: An example system for receiving gas expelled from a core sample of a formation may include a tubular element. A core chamber may be disposed within the first tubular element. A gas and drilling fluid separator may be in fluid communication with the core chamber. The tubular element may be an inner barrel assembly of a core sample assembly that is disposed within a borehole. A core sample may be contained within the inner barrel assembly and may be retrieved at the surface. Gas may be expelled from the core sample as it is retrieved, and the gas and drilling fluid separator may separate the expelled gas from suspension with a drilling fluid for analysis.

Abstract: A system for obtaining a core sample from a wellbore includes a housing having a core opening at a first end of the housing and an end wall at a second end of the housing. A balancing piston is positioned within the housing to define a sample chamber between the balancing piston and the core opening. An equalization chamber is defined between the balancing piston and the end wall. A core piston is sealingly positioned in the core opening.

Abstract: A method for obtaining a core sample from a wellbore using a coring tool is disclosed. The method includes providing an outer barrel in the wellbore. The wellbore and outer barrel are at least partially filled with a drilling fluid. The method further includes lowering an inner barrel partially into the drilling fluid and displacing the drilling fluid in the inner barrel with a coring fluid.

Abstract: There is disclosed herein drilling apparatus, in particular for use in the field of oil prospecting, comprising: a first tubular member (1, 2, 3); a second tubular member (6, 7, 8, 9) mounted at least partly within the first tubular member so as to be reciprocally free in rotation with respect to the first tubular member about an axis (5); and a drill bit (4) operatively connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling, characterised in that: the drilling apparatus further comprises a restoring member (18, 36) for applying a forces between the first tubular member and the second tubular member at least in respective first axial directions in response to relative displacement of the first tubular member and the second tubular member in the respective opposite axial directions. Also provided are a tubular assembly and a method of assembling tubular members.

Abstract: A coring apparatus may be integrated with fluid analysis capabilities for in situ analysis of core samples from a subterranean formation. An instrumented coring apparatus may include an inner core barrel; an outer core barrel; a coring bit; and an instrumented core barrel having an analysis device in fluid communication with the inner core barrel.

Abstract: Disclosed are systems and methods of coupling plain end pipes. One system includes a coupling sleeve having opposing upper and lower ends and a plurality of axially extending slots defined in each end, wherein the upper end is configured to receive an end of a first pipe and the lower end is configured to receive an end of a second pipe, an upper sliding ring disposed about the coupling sleeve and axially movable in a first direction to force the upper end into gripping engagement with an outer surface of the first pipe, and a lower sliding ring disposed about the coupling sleeve and axially movable in a second direction to force the lower end into gripping engagement with an outer surface of the second pipe.

Abstract: A coring apparatus may be integrated with fluid analysis capabilities for in situ analysis of core samples from a subterranean formation. An instrumented coring apparatus may include an inner core barrel; an outer core barrel; a coring bit; and an instrumented core barrel having an analysis device in fluid communication with the inner core barrel.

Abstract: There is disclosed herein drilling apparatus, in particular for use in the field of oil prospecting, comprising: a first tubular member (1, 2, 3); a second tubular member (6, 7, 8, 9) mounted at least partly within the first tubular member so as to be reciprocally free in rotation with respect to the first tubular member about an axis (5); and a drill bit (4) operatively connected to one of the first or second tubular members so as to be rotated in response to the one tubular member being turned in order to effect drilling, characterised in that: the drilling apparatus further comprises a restoring member (18, 36) for applying a forces between the first tubular member and the second tubular member at least in respective first axial directions in response to relative displacement of the first tubular member and the second tubular member in the respective opposite axial directions. Also provided are a tubular assembly and a method of assembling tubular members.