Abstract: A core drill assembly with replaceable fluid nozzles permitting effective total flow area adjustment (TFA), substantial optimization of hydraulic force at the cutting face to improve rate of penetration (ROP) and core quality. At least one seal assembly to restrict drilling fluid flow while permitting mutual rotation between the core head ID and the lower shoe is disposed in an annulus defined therebetween.

Abstract: A sponge core barrel for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of presaturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and presaturation of multiple, sections of inner tube to form a single, continuous chamber.

Abstract: A sponge core barrel is disclosed for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of presaturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and presaturation of multiple sections of inner tube to form a single, continuous chamber.

Abstract: A sponge core barrel for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of presaturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and presaturation of multiple, sections of inner tube to form a single, continuous chamber.

Abstract: A sponge core barrel for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of presaturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and presaturation of multiple, sections of inner tube to form a single, continuous chamber.

Abstract: A sponge core barrel for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of pre-saturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and pre-saturation of multiple, sections of inner tube to form a single, continuous chamber.

Abstract: A sponge core barrel for use in performing sponge coring and methods of assembling the sponge core barrel, as well as methods of performing sponge coring. The sponge core barrel includes an outer barrel assembly, a core bit secured to a lower end thereof, and an inner barrel assembly disposed therein. The inner barrel assembly may comprise multiple, sponge-lined inner tube sections and may also include a near-bit swivel assembly. The sponge core barrel may include a piston assembly configured to be released by contact with a core sample without imparting high compressive forces to the core. The sponge core barrel may also include a pressure compensation mechanism and, optionally, a thermal compensation mechanism cooperatively configured to maintain the pressure of presaturation fluid. The sponge core barrel may also include a valve assembly enabling the make-up and presaturation of multiple sections of inner tube to form a single, continuous chamber.

Abstract: A well coring apparatus is provided with the capability for monitoring the length of the core in the inner barrel (32) of a core barrel (16) and the rate at which the core enters the inner barrel (32). The device includes a Sonic Core Monitor (78) which is disposed in the upper end of the inner barrel (32) and a piston (68) which is disposed in the lower end thereof. The inner barrel (32) is filled with a pressurized fluid. The Sonic Core Monitor (78) generates an ultrasonic pulse that is transmitted down to the surface of the piston (68) and reflected back up to the Sonic Core Monitor (78). The time between the transmitted and received pulse is then measured and distance determined therefrom. Both length of core and rate of core entry into the inner barrel (32) can then be determined. If the core is proceeding at too slow a rate, a valve (50) can be opened to allow drilling fluid to bypass the core barrel (16). This provides the surface operator with an indication that a jam has occurred.

Abstract: A well coring apparatus is provided with the capability for monitoring the length of the core in the inner barrel (32) of a core barrel (16) and the rate at which the core enters the inner barrel (32). The device includes a Sonic Core Monitor (78) which is disposed in the upper end of the inner barrel (32) and a piston (68) which is disposed in the lower end thereof. The Sonic Core Monitor (78) generates an ultrasonic pulse that is transmitted down to the surface of the piston (68) and reflected back up to the Sonic Core Monitor (78). The time between the transmitted and received pulse is then measured and distance determined therefrom. Both length of core and rate of core entry into the inner barrel (32) can then be determined. If the core is proceeding at too slow a rate, a valve (50) can be opened to allow drilling fluid to bypass the core barrel (16). This provides the surface operator with an indication that a jam has occurred.

Abstract: A method for determining the productivity of a well site includes extracting a core with sponge coring techniques and measuring the parameters of the core. The parameters measured are porosity, permeability and percent mobile oil. A core factor is calculated which is the square root of the product of permeability and porosity and indicates the space available in the core for oil production. The core factor is multiplied by the percent mobile oil to provide a Production Index. The Production Index indicates the capacity of a given oil well to produce oil. With the Production Index data, perforations are selectively placed in various areas along the longitudinal axis of a well casing (38) to selectively allow communication between the interior of the well casing and a formation of interest. In this manner, only areas having high oil mobility are communicated within a given region of the formation of interest.

Abstract: A well coring apparatus (10) includes an outer barrel (12) and an inner barrel (18). The inner barrel (18) is sealed at one end with a sealing member (80) and has a reciprocating piston (70) disposed in the other end thereof. An O-ring (68) is disposed at the receiving end of the inner barrel (18) to provide a seal therefor. Spring members (76) provide a restrictive force to the piston (70). A sponge (50) is disposed around the inner walls of the inner barrel (18) for contacting the core (82). A fluid is disposed in the inner space (78) of the inner barrel (18) and pressurized. Reciprocation upward of the piston (70) causes the fluid to flow therefrom out the receiving end of the inner barrel (18). This flow of fluid washes the sides of the core (82) to prevent drilling mud from caking about the surfaces thereof and preventing proper transfer of fluids contained within the core (82) to the sponge (50).

Abstract: A well coring apparatus (10) includes an outer barrel (12) and an inner barrel (18). A hollow sponge (50) is disposed along a liner (52) for insertion into the inner barrel (18). The sponge (50) is operable to absorb subterranean fluid from a well core (54). A plurality of reinforcing members (56) are disposed on the inner surface of the liner (52) to prevent movement of the sponge (50) with respect thereto. A plurality of orifices (58) are disposed in the surface of the liner (52) to allow gas and/or fluid to escape from the interior thereof when the subterranean fluid contained within the core (54) bleeds into the sponge (50).

Abstract: A well coring apparatus (10) includes an outer barrel (12) and an inner barrel (18). The inner barrel (18) is sealed with a rupturable diaphragm (24) and a check valve (49). A sponge (50) is disposed around the inner walls of the inner barrel (18) for contacting the core (58). A fluid (54) is disposed in the sealed inner barrel (18) to prewet the sponge (50). A piercer (32) is reciprocally disposed within the outer barrel (12) and has a conical shaped surface (38), the apex of which is operable to pierce the diaphragm (24). In response to forming of the core (58), the fluid (54) displaced by the core (58) prevents drilling mud from being disposed between the core (58) and the sponge (50).