Abstract: For a pressure packing with a buffer gas barrier into which a buffer gas is fed via a buffer gas feeding line, a sensing line is provided that is connected at a first end to a vent volume in the pressure packing with an opposite second end of the sensing line being closed, so that there is no gas flow in the sensing line. A pressure regulator is connected to the buffer gas feeding line for setting the buffer gas pressure in the buffer gas feeding line, whereas, during operation of the pressure packing, the pressure in the sensing line is used as pilot pressure for the pressure regulator for setting the buffer gas pressure.

Abstract: The disclosure relates to a method of delaying viscosification of a well treatment fluid within a well or within a subterranean formation penetrated by a well by introducing into the well a hydratable viscosifying agent of particulates having a minimum of 40% retention on a 60 mesh screen and a minimum of 1% retention on a 20 mesh screen.

Abstract: The disclosure relates to a method of delaying viscosification of a well treatment fluid within a well or within a subterranean formation penetrated by a well by introducing into the well a hydratable viscosifying agent of particulates having a minimum of 40% retention on a 60 mesh screen and a minimum of 1% retention on a 20 mesh screen.

Abstract: The disclosure relates to a method of delaying viscosification of a well treatment fluid within a well or within a subterranean formation penetrated by a well by introducing into the well a hydratable viscosifying agent of particulates having a minimum of 40% retention on a 60 mesh screen and a minimum of 1% retention on a 20 mesh screen.

Abstract: An unloader ring 20 has a plurality of unloader fingers 21 passing through intake channels 16 of the intake valve 5 arranged in the ring-shaped intake chamber 11 such that the unloader ring 20 is guided on the wall 24, 31 of the intake chamber 11, where it is arranged displaceably by means of the circumferential surface 23 of the unloader ring 20 on the outside radially or by the circumferential surface 30 of the unloader ring 20 on the inside radially. A radial step 25 is provided on the circumferential surface 23 of the unloader ring on the outside radially or on the circumferential surface 30 of the unloader ring 20 on the inside radially, and a control chamber 26 is formed between the wall 24, 31 of the intake chamber 11 and the radial step 25, this control chamber being connected to a control line 27 for supplying a control medium into the control chamber 26.

Abstract: A shutoff valve (2) which is switchable in a cycled manner for capacity regulation by temporarily shutting off the intake gas feed is designed as a multi-element ring valve, and is directly actuated by means of an electromagnet (12). The actuating forces for switching the shutoff valve (2) may be kept small via pressure compensation from the intake gas feed (3) to behind the anchor plate (9).

Abstract: A cylinder head for a two-stage reciprocating piston compressor includes an intercooler that is designed as a cooled overflow channel between the pressure side of the first stage and the suction side of the second stage, wherein the overflow channel has a substantially slot-like cross-section, and the overflow channel is in addition divided by at least one indirectly cooled center rib so that therefrom at least two overflow channel portions and are created. The cylinder head has a cylinder head upper part and a cylinder head lower part, the cross-section of the indirectly cooled center rib is divided in its longitudinal extent thereby forming a passage gap between the overflow channels and that run on both sides, and one portion of the center rib is formed from the cylinder head upper part and the other portion of the center rib is formed from the cylinder head lower part.

Abstract: Set retarders of copolymers of at least one polymerizable ethylenically unsaturated monomer and at least one alkoxylated monomer are capable of delaying the hardening of a cementitious slurry when introduced into a subterranean formation until a downhole temperature greater than or equal to 500° F. is obtained, even in the absence of an intensifier.

Abstract: Due to increasingly strict requirements and regulations, it is becoming more and more important for piston compressors to reduce the amount of leakage of operating medium through the seal of the piston rod. Conventional seals comprising packing rings and/or packing ring combinations always have a certain amount of leakage, both during operation and when at standstill, which is why they are not usable for certain applications, or the complexity involved in such a seal increases considerably. A further problem involving the seals of piston rods relates to transverse movements by piston rods during which the sealing action of the seal must be maintained. Proposed is, therefore, a sealing arrangement according to the principle of a sealing medium barrier providing that the sealing elements 8, 9 are arranged in radial direction at a distance relative to the radial end of the recess 10 that receives the sealing elements 8, 9.

Abstract: The disclosure relates to a method of delaying viscosification of a well treatment fluid within a well or within a subterranean formation penetrated by a well by introducing into the well a hydratable viscosifying agent of particulates having a minimum of 40% retention on a 60 mesh screen and a minimum of 1% retention on a 20 mesh screen.

Abstract: A shutoff valve (2) which is switchable in a cycled manner for capacity regulation by temporarily shutting off the intake gas feed is designed as a multi-element ring valve, and is directly actuated by means of an electromagnet (12). The actuating forces for switching the shutoff valve (2) may be kept small via pressure compensation from the intake gas feed (3) to behind the anchor plate (9).

Abstract: The invention relates to a cylinder head (1) for a two-stage reciprocating piston compressor, comprising an intercooler (9) that is designed as a cooled overflow channel (14) between the pressure side of the first stage and the suction side of the second stage, wherein the overflow channel (14) has a substantially slot-like cross-section, and the overflow channel (14) is in addition divided by at least one indirectly cooled center rib (15) so that therefrom at least two overflow channel portions (14?) and (14?) are created, wherein the cylinder head (1) has a cylinder head upper part (2) and a cylinder head lower part (3), the cross-section of the indirectly cooled center rib (15) is divided in its longitudinal extent thereby forming a passage gap between the overflow channels (14?) and (14?) that run on both sides, and one portion of the center rib (15) is formed from the cylinder head upper part (2) and the other portion of the center rib (15) is formed from the cylinder head lower part (3).

Abstract: To implement a very compact cylinder head having an integrated unloader, it is provided that a unloader ring 20 having a plurality of unloader fingers 21 passing through the intake channels 16 of the intake valve 5 is arranged in the ring-shaped intake chamber 11 such that the unloader ring 20 is guided on the wall 24, 31 of the intake chamber 11, where it is arranged displaceably by means of the circumferential surface 23 of the unloader ring 20 on the outside radially or by the circumferential surface 30 of the unloader ring 20 on the inside radially; a radial step 25 is provided on the circumferential surface 23 of the unloader ring on the outside radially or on the circumferential surface 30 of the unloader ring 20 on the inside radially, and a control chamber 26 is formed between the wall 24, 31 of the intake chamber 11 and the radial step 25, this control chamber being connected to a control line 27 for supplying a control medium into the control chamber 26 and a lower stop (32) for the unloader ring (2

Abstract: Methylhydroxyethyl cellulose may be used as an additive in cement slurries in the treatment of wells to prevent or reduce the occurrence of gas channeling. In addition to acting as a gas control additive, methylhydroxyethyl cellulose controls fluid loss, minimizes free fluid and stabilizes foam during cementing of the well.

Abstract: Synthesis gas is more effectively produced from the underground gasification of coal from a coal seam when the casing lining is cemented with a cementitious slurry containing a cementitious material, graphite and an aluminum silicate, such as metakaolin. The cementitious slurry of the cement mix sets as a cement sheath at bottomhole static temperatures less than or equal to 65° C. The set cement may withstand extreme dry heat temperatures which are greater than or equal to 800° C.

Abstract: Methylhydroxyethyl cellulose may be used as an additive in cement slurries in the treatment of wells to prevent or reduce the occurrence of gas channeling. In addition to acting as a gas control additive, methylhydroxyethyl cellulose controls fluid loss, minimizes free fluid and stabilizes foam during cementing of the well.

Abstract: A gas-proof sealing packing of a compressor includes a scraper recess on the crankcase-side end containing a gas-proof scraper ring, a sealing ring recess on the cylinder-side end containing a sealing ring arrangement (18), a barrier recess located axially between the scraper recess (15) and the sealing ring recess (17), and a drain line in the sealing packing that is connected with the space between the barrier recess and the scraper recess.

Abstract: Set retarders of copolymers of at least one polymerizable ethylenically unsaturated monomer and at least one alkoxylated monomer are capable of delaying the hardening of a cementitious slurry when introduced into a subterranean formation until a downhole temperature greater than or equal to 500° F. is obtained, even in the absence of an intensifier.

Abstract: Synthesis gas is more effectively produced from the underground gasification of coal from a coal seam when the casing lining is cemented with a cementitious slurry containing a cementitious material, graphite and an aluminum silicate, such as metakaolin. The cementitious slurry of the cement mix sets as a cement sheath at bottomhole static temperatures less than or equal to 65° C. The set cement may withstand extreme dry heat temperatures which are greater than or equal to 800° C.

Abstract: Due to increasingly strict requirements and regulations, it is becoming more and more important for piston compressors to reduce the amount of leakage of operating medium through the seal of the piston rod. Conventional seals comprising packing rings and/or packing ring combinations always have a certain amount of leakage, both during operation and when at standstill, which is why they are not usable for certain applications, or the complexity involved in such a seal increases considerably. A further problem involving the seals of piston rods relates to transverse movements by piston rods during which the sealing action of the seal must be maintained. Proposed is, therefore, a sealing arrangement according to the principle of a sealing medium barrier providing that the sealing elements 8, 9 are arranged in radial direction at a distance relative to the radial end of the recess 10 that receives the sealing elements 8, 9.