An apparatus for cutting into a subterranean formation includes a body and multiple cutting blades distributed around a circumference of the body. The cutting blades are configured to cut into the subterranean formation in response to being rotated. Each cutting blade includes a ball embedded in the respective cutting blade. At least a portion of the ball protrudes towards the subterranean formation from the respective cutting blade in which the ball is embedded. Each ball is configured to roll against the subterranean formation to reduce friction while the cutting blades are rotating.

The present invention relates to a wireline cased-hole roller (WCRO) for deployment during a logging operation that reduces slickline or e-line cable contact and drag in the cased hole section of a wellbore. Arrays of WCROs, clamped on the slickline or e-line, reduce logging tensions and improve force transmission from surface down to the tool cable head by significantly reducing the cased-hole cable drag. They also permit the use of lower grade cables or winches in certain environments due to lower logging tensions. Another benefit is the mitigation of cased hole cable wear zones since the cable is suspended above the casing, liner or tubing. In high-angle or horizontal wells, arrays of WCROs aid conveyance and improve tractor performance by reducing the cable drag force which has to be overcome to reach the target zone.

A downhole sensor position adjustment device on a downhole sensor assembly comprising a set of centralizers and a sensor array coupled to an adjustable framework radially positionable by an actuator. The actuator includes an extend-retract mechanism to radially position the sensor array a predetermined radial distance to an inner surface of a casing. A controller communicatively coupled to the extend-retract mechanism is configured to actuate the extend-retract mechanism. A positioning sensor provides feedback of the predetermined radial distance of the sensor array to the inner surface of the casing.

The low friction wireline standoff improves wireline cable performance during borehole logging operations. The use of low friction wireline standoffs ameliorates the effects of wireline cable differential sticking, wireline cable key-seating, and high wireline cable drags, by reducing or eliminating contact of the wireline cable with the borehole wall during the logging operation. The low friction wireline standoff comprises external wheels mounted on two finned half shells that clamp onto the wireline with precision cable inserts which are manufactured to fit a wide range of logging cables. The wheels reduce the cable drag down-hole resulting in lower surface logging tensions, aiding conveyance in deep and deviated wells.

A centralizer assembly installed on a casing section. A bow spring assembly having bow spring members is installed around the outer surface of the casing section and can rotate about the outer surface of the casing section. At least one portion of the casing section is swaged to increase the outer diameter of that section. Bow spring heel supports prevent bow spring members from contacting the outer surface of the central casing section when compressed. Non-abrasive materials prevent damage to wellhead or other polished bore receptacles.

A centralizer assembly installed on a casing section. A bow spring assembly having bow spring members is installed around the outer surface of the casing section and can rotate about the outer surface of the casing section. At least one portion of the casing section is swaged to increase the outer diameter of that section. Bow spring heel supports prevent bow spring members from contacting the outer surface of the central casing section when compressed. Non-abrasive materials prevent damage to wellhead or other polished bore receptacles.

A device for centering a sensor assembly in a bore comprises a plurality of arm assemblies connected first and second support members. Each arm assembly comprises a first arm pivotally connected to the first support member, a second arm pivotally connected to the second support member, and a third arm pivotally connected between the first and second arms. The third arm is pivotally connected to a third support member positioned axially between the first and second support members. The third arm extends across the longitudinal axis of the device so that in use each arm assembly contacts opposite sides of the bore to centralise the sensor assembly in the bore.

The low friction wireline standoff improves wireline cable performance during borehole logging operations. The use of low friction wireline standoffs ameliorates the effects of wireline cable differential sticking, wireline cable key-seating, and high wireline cable drags, by reducing or eliminating contact of the wireline cable with the borehole wall during the logging operation. The low friction wireline standoff comprises external wheels mounted on two finned half shells that clamp onto the wireline with precision cable inserts which are manufactured to fit a wide range of logging cables. The wheels reduce the cable drag down-hole resulting in lower surface logging tensions, aiding conveyance in deep and deviated wells.

The present invention relates to a system for contaminant extraction in a borehole extending from a surface of the Earth through a water permeable layer and into an underlying production zone, the system comprising: an outer casing located within the borehole and extending through the water permeable layer; a production pipe located within the casing and extending towards the production zone; a filter assembly occupying at least part of an intermediate zone between the outer casing and the production pipe, wherein the filter assembly is configured to capture contaminants before they enter the water permeable layer and/or before they are released into the atmosphere, the filter assembly comprising: a lower solids filtering stage configured to filter solid contaminants; and an upper fluids filtering stage configured to filter fluid contaminants migrating from the production zone through the lower solids filtering stage; and sealing means for preventing the uncontrolled leakage of contaminants from the intermediate zone. Methods for contaminant extraction, a contaminant filtration system and solid and fluid filter modules are also disclosed.

A wheel assembly configured to detachably connect to a downhole tool to thereby reduce friction between the downhole tool and a sidewall of a wellbore through which the downhole tool is conveyed. The wheel assembly may include an axle configured to contact a sidewall of the downhole tool, wherein the axle comprises a bore extending therethrough, a wheel rotatably connected to the axle such that the wheel extends around at least a portion of the axle and the bore, and a fastener configured to be disposed at least partially within the bore and extend out of the bore into the sidewall of the downhole tool to detachably connect the axle to the downhole tool.