Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston may have an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to enable a constant amount of flow exiting the axial end of the tool to be achieved while diverting away excess flow through the side.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string is described. The device includes a cylindrical tube with holes in its periphery. Flow enters the device through an upper end of the tube and a portion of the flow exits through the lower end of the tube. In addition, some of the flow is diverted through the peripheral holes. A valve piston is supported near the lower end of the tube by a spring of approximately constant force through its range of travel. The valve piston moves axially as the flow rate through the tube changes flow rate to ensure that a substantially constant amount of flow exits through the lower end, while the excess flow is diverted from the tube through the peripheral holes. A means of damping or stopping the axial movement of the valve piston is included in the device.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string is described. The device includes a cylindrical tube with holes in its periphery. Flow enters the device through an upper end of the tube and a portion of the flow exits through the lower end of the tube. In addition, some of the flow is diverted through the peripheral holes. A valve piston is supported near the lower end of the tube by a spring of approximately constant force through its range of travel. The valve piston moves axially as the flow rate through the tube changes flow rate to ensure that a substantially constant amount of flow exits through the lower end, while the excess flow is diverted from the tube through the peripheral holes. A means of damping or stopping the axial movement of the valve piston is included in the device.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string is described. The device includes a cylindrical tube with holes in its periphery. Flow enters the device through an upper end of the tube and a portion of the flow exits through the lower end of the tube. In addition, some of the flow is diverted through the peripheral holes. A valve piston is supported near the lower end of the tube by a spring of approximately constant force through its range of travel. The valve piston moves axially as the flow rate through the tube changes flow rate to ensure that a substantially constant amount of flow exits through the lower end, while the excess flow is diverted from the tube through the peripheral holes. A means of damping or stopping the axial movement of the valve piston is included in the device.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston may have an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to enable a constant amount of flow exiting the axial end of the tool to be achieved while diverting away excess flow through the side.

Abstract: A system for recovering production fluid includes a return string for receiving fluid from a lateral section of a wellbore. The return string can extend from a surface of a terrestrial formation through at least a portion of the wellbore. The system also includes an injection string for communicating fluid from the surface of the terrestrial formation to the lateral section of the wellbore. The injection string includes a first injection string section located at a distal end of the injection string and for communicating fluid through at least a portion of the lateral section of the wellbore. The injection string includes a second injection string section located at a proximal end of the injection string and for communicating fluid from the surface of the terrestrial formation to the first injection string section. The second injection string section includes a smaller cross-sectional area than the first injection string section.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston may have an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to enable a constant amount of flow exiting the axial end of the tool to be achieved while diverting away excess flow through the side.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string is described. The device includes a cylindrical tube with holes in its periphery. Flow enters the device through an upper end of the tube and a portion of the flow exits through the lower end of the tube. In addition, some of the flow is diverted through the peripheral holes. A valve piston is supported near the lower end of the tube by a spring of approximately constant force through its range of travel. The valve piston moves axially as the flow rate through the tube changes flow rate to ensure that a substantially constant amount of flow exits through the lower end, while the excess flow is diverted from the tube through the peripheral holes. A means of damping or stopping the axial movement of the valve piston is included in the device.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston may have an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to enable a constant amount of flow exiting the axial end of the tool to be achieved while diverting away excess flow through the side.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston may have an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to enable a constant amount of flow exiting the axial end of the tool to be achieved while diverting away excess flow through the side.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston has an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to ensure that a constant amount of flow exiting the axial end of the tool is achieved while diverting away excess flow through the side.

Abstract: A downhole tool may include a tubular member having an axis, a wall with a bore, and an orifice extending radially from the bore through the wall. A piston may be configured to be co-axially mounted in the bore of the tubular member and be axially reciprocated therein, the piston having a piston bore. An aperture may extend radially from the piston bore to the bore of the tubular member. First and second glands formed in an outer surface adjacent the aperture. The first gland may be axially spaced apart from the second gland. In addition, a seal system can be configured to be mounted to the piston. The seal system can include a primary seal for the first gland, a secondary seal for the second gland, and the secondary seal is harder than the primary seal.

Abstract: A device for limiting the flow of drilling fluid through a section of drill string includes a body with a hole in the periphery. Flow enters the device through one axial end, at least a portion of the flow exits through the other axial end. Some of the fluid flow can be diverted through the peripheral hole. A spring-biased axial piston has an approximately constant force throughout its range of travel. The piston moves axially in response to the changing fluid flow rate to ensure that a constant amount of flow exiting the axial end of the tool is achieved while diverting away excess flow through the side.

Abstract: Equipment and methods which may be used in conjunction with an underbalanced well completion. In a described embodiment, a valve for use in a subterranean well in conjunction with a tool conveyed through the valve in a container is provided. The valve includes a passage formed longitudinally through the valve, a closure assembly which selectively permits and prevents flow through the passage, and an engagement device which engages the container as the tool is conveyed through the passage. The closure assembly permits flow through the passage when the container is conveyed into the passage, and the closure assembly prevents flow through the passage when the container is removed from the passage. Engagement between the container and the engagement device separates the tool from the container.

Abstract: Affinity chromatography media are prepared by reacting mono or di-chloro triazine dyes with a solid support matrix containing free hydroxy or amino groups in the presence of an alkali metal hydroxide and an alkali metal salt. In the absence of cyanogen bromide activation, the linkage to the support is entirely via the triazine ring giving high and specific protein-binding capacity. Suitable support matrices include polymers and copolymers of agarose, dextrose, dextran and acrylamide with agarose being particularly preferred. Dye binding levels are much higher than those obtained in the presence of carbonates or bicarbonates.Mono-chlorotriazinyl dyes are bound at a pH which is preferably above 9.5. The reaction time is about 40-60 hours at room temperature, however this may be reduced if the reaction temperature is increased. Dichlorotriazinyl dyes are bound at pH 8 to 12.5 in a few hours at room temperature.

Abstract: A size for glass fibers capable of protecting the fibers from mutual abrasion using 0.6% coating solids or less, and comprising a cationic starch derivative of a tertiary amine along with a cationic lubricant that is generally devoid of primary amines.