Abstract: Overburden stress is applied to a core rock sample in a sleeve. Pressure is applied to pores in the core rock sample. An overburden fluid pressure indicative of the overburden stress and pore fluid pressure indicative of the pore pressure is measured. A difference between the overburden fluid pressure and pore fluid pressure is determined. The measuring and determination of the difference is repeated over a period of time. A rate of change of the difference over the period of time is determined. An indication of the rate of change meeting a threshold level is output indicative of the overburden stress transferring into and throughout the core rock sample.

Abstract: A method includes determining a perforation tunnel geometry of a perforation tunnel in a solid sample, the perforation tunnel created by activating a shaped charge in proximity to the solid sample. The method also includes performing a first flow test on the solid sample and creating an analog aperture having an aperture geometry in a solid sample analog of the solid sample, wherein the aperture geometry and the perforation tunnel geometry satisfies a similarity threshold. The method also includes performing a second flow test on the solid sample analog and determining a shaped charge effect based on a comparison between a second flow test result and a first flow test result.

Abstract: Overburden stress is applied to a core rock sample in a sleeve. Pressure is applied to pores in the core rock sample. An overburden fluid pressure indicative of the overburden stress and pore fluid pressure indicative of the pore pressure is measured. A difference between the overburden fluid pressure and pore fluid pressure is determined. The measuring and determination of the difference is repeated over a period of time. A rate of change of the difference over the period of time is determined. An indication of the rate of change meeting a threshold level is output indicative of the overburden stress transferring into and throughout the core rock sample.

Abstract: A method includes determining a perforation tunnel geometry of a perforation tunnel in a solid sample, the perforation tunnel created by activating a shaped charge in proximity to the solid sample. The method also includes performing a first flow test on the solid sample and creating an analog aperture having an aperture geometry in a solid sample analog of the solid sample, wherein the aperture geometry and the perforation tunnel geometry satisfies a similarity threshold. The method also includes performing a second flow test on the solid sample analog and determining a shaped charge effect based on a comparison between a second flow test result and a first flow test result.

Abstract: To optimize the efficiency of a perforating tool system, downhole conditions may be simulated to determine the optimal configuration for the perforating tool system. A simulated wellbore is disposed in a simulated wellbore case and coupled to a formation sample. The simulated wellbore comprises the perforating tool system and one or more filler discs that consume a volume of the simulated wellbore. The filler discs are used to control the dynamic underbalance for a given simulation of a perforating tool system. One or more measurements associated with the perforating tool system along with one or more images may be generated after explosive charges of the perforating tool system are detonated. The perforating tool system may be modified based, at least in part, on the one or more measurements and the one or more images for the specific dynamic underbalance of the simulation.

Abstract: A method and apparatus are provided for controlling wellbore pressure within a wellbore during a perforation event by changing a state of a valve system multiple times. Information generated about the wellbore pressure within the wellbore may be received. A state of the valve system, which is positioned relative to a chamber within the wellbore, may be changed multiple times based on the information received to create a plurality of pressure conditions that substantially match a reference pressure profile. Each of the plurality of pressure conditions is selected from one of an underbalance condition and an overbalance condition.

Abstract: To optimize the efficiency of a perforating tool system, downhole conditions may be simulated to determine the optimal configuration for the perforating tool system. A simulated wellbore is disposed in a simulated wellbore case and coupled to a formation sample. The simulated wellbore comprises the perforating tool system and one or more filler discs that consume a volume of the simulated wellbore. The filler discs are used to control the dynamic underbalance for a given simulation of a perforating tool system. One or more measurements associated with the perforating tool system along with one or more images may be generated after explosive charges of the perforating tool system are detonated. The perforating tool system may be modified based, at least in part, on the one or more measurements and the one or more images for the specific dynamic underbalance of the simulation.

Abstract: A method of performing a rock core flow performance test includes increasing a pressure applied to at least one surface of the rock core to a first pressure, measuring the pressure on a wellbore facing axial end of the rock core to determine a time interval over which the measured pressure drops from a second pressure to a third pressure, and determining a high pressure production ratio of the rock core based on the time interval.

Abstract: A method and apparatus are provided for controlling wellbore pressure within a wellbore during a perforation event by changing a state of a valve system multiple times. Information generated about the wellbore pressure within the wellbore may be received. A state of the valve system, which is positioned relative to a chamber within the wellbore, may be changed multiple times based on the information received to create a plurality of pressure conditions that substantially match a reference pressure profile. Each of the plurality of pressure conditions is selected from one of an underbalance condition and an overbalance condition.

Abstract: Disclosed is a method of testing the effectiveness of perforations and well treatments to enhance production, wherein tomographic image data is collected while fluid flow tests are conducted on a formation sample and thereafter three dimensional images are created and analyzed.

Abstract: A rock core flow test system comprises a first high pressure accumulator, a second high pressure accumulator, and a fast opening flow control device coupled to a wellbore facing end of the rock core. The fast opening flow control device opens when a pressure differential across the flow control device exceeds a predetermined threshold. The first high pressure accumulator is coupled to at least one of a pore end of the rock core and a radial surface of the rock core. The second high pressure accumulator is coupled to the fast opening flow control device. The system further comprises a pressure sensor coupled to the rock core flow test system between the fast opening flow control device and the second high pressure accumulator.

Abstract: A method of performing a rock core flow performance test includes increasing a pressure applied to at least one surface of the rock core to a first pressure, measuring the pressure on a wellbore facing axial end of the rock core to determine a time interval over which the measured pressure drops from a second pressure to a third pressure, and determining a high pressure production ratio of the rock core based on the time interval.

Abstract: A method of adjusting a pressure reduction to occur in a wellbore following firing of at least one perforating gun can include determining a desired free gun volume which corresponds to a desired pressure reduction in the wellbore resulting from firing of the perforating gun, and varying a free gun volume of the perforating gun until the free gun volume is substantially the same as the desired free gun volume. A well system can include at least one perforating gun positioned in a wellbore, the perforating gun comprising multiple perforating charges and a free gun volume, and the free gun volume being reduced by presence of a flowable material about the multiple perforating charges.

Abstract: A rock core flow test system comprises a first high pressure accumulator, a second high pressure accumulator, and a fast opening flow control device coupled to a wellbore facing end of the rock core. The fast opening flow control device opens when a pressure differential across the flow control device exceeds a predetermined threshold. The first high pressure accumulator is coupled to at least one of a pore end of the rock core and a radial surface of the rock core. The second high pressure accumulator is coupled to the fast opening flow control device. The system further comprises a pressure sensor coupled to the rock core flow test system between the fast opening flow control device and the second high pressure accumulator.

Abstract: A method of adjusting a pressure reduction to occur in a wellbore following firing of at least one perforating gun can include determining a desired free gun volume which corresponds to a desired pressure reduction in the wellbore resulting from firing of the perforating gun, and varying a free gun volume of the perforating gun until the free gun volume is substantially the same as the desired free gun volume. A well system can include at least one perforating gun positioned in a wellbore, the perforating gun comprising multiple perforating charges and a free gun volume, and the free gun volume being reduced by presence of a flowable material about the multiple perforating charges.