摘要:
A drill string caliper includes a mandrel configured to be coupled within a drill string. At least one laterally extensible arm is coupled to an exterior of the mandrel. A biasing device is configured to urge the at least one arm into contact with a wall of a wellbore. A sensor is configured to generate an output signal corresponding to a lateral extent of the at least one arm.
摘要:
A method and apparatus for measuring the pressure of a formation penetrated by a wellbore is provided. A downhole tool is positioned in the wellbore and a probe is extended therefrom into sealing engagement with the formation. A piston in the probe is retracted therein where by a cavity is defined for receiving a fluid from the formation. A pressure underbalance in the cavity draws fluid from the formation into the cavity. An oscillator may be used to fluctuate the flow of fluid into the cavity. A pressure gauge is used to measure the pressure of fluid in the cavity.
摘要:
A composition for use in an oil chamber of a tool includes a hydraulic oil; and a surfactant, wherein the surfactant is present at an amount sufficient to form micelles in the hydraulic oil. The composition may further include an amphiphilic copolymer. A method includes providing a hydraulic fluid composition comprising a hydraulic oil and a surfactant capable of forming micelles in the hydraulic oil; and filling a hydraulic chamber in the tool with the hydraulic fluid composition. The hydraulic fluid composition may further include an amphiphilic copolymer.
摘要:
Methods and apparatus to control a formation testing operation based on a mudcake leakage are disclosed. A disclosed example method for use with a downhole tool disposed in a wellbore comprises measuring a property of a mudcake layer at a first location in a wellbore, determining a value representative of an estimated leakage through the mudcake layer based on the property, and determining, based on the value, whether to continue a formation testing operation.
摘要:
Methods and apparatus to control a formation testing operation based on a mudcake leakage are disclosed. A disclosed example method for use with a downhole tool disposed in a wellbore comprises measuring a property of a mudcake layer at a first location in a wellbore, determining a value representative of an estimated leakage through the mudcake layer based on the property, and determining, based on the value, whether to continue a formation testing operation.
摘要:
The present invention provides an apparatus for use in perforating a well having a plurality of explosive charges. Each explosive charge is adapted to generate a perforation tunnel in the formation adjacent to the well. In one embodiment, explosive charges are oriented to create perforation tunnels that converge at a location within the formation in order to create a fracture initiation plane capable of mitigating or avoiding hydraulic fracturing complications.
摘要:
A composition for use in an oil chamber of a tool includes a hydraulic oil; and a surfactant, wherein the surfactant is present at an amount sufficient to form micelles in the hydraulic oil. The composition may further include an amphiphilic copolymer. A method includes providing a hydraulic fluid composition comprising a hydraulic oil and a surfactant capable of forming micelles in the hydraulic oil; and filling a hydraulic chamber in the tool with the hydraulic fluid composition. The hydraulic fluid composition may further include an amphiphilic copolymer.
摘要:
A method for determining formation pressure at a depth region of formations surrounding a borehole, including: keeping track of the time since cessation of drilling at the depth region; deriving formation permeability at the depth region; causing wellbore pressure to vary periodically in time and determining, at the depth region, the periodic and non-periodic component of pressure measured in the formations; determining, using the time, the periodic component and the permeability, the formation pressure diffusivity and transmissibility and an estimate of the size of the pressure build-up zone around the wellbore at the depth region; determining, using the time, the formation pressure diffusivity and transmissibility, and the non-periodic component, the leak-off rate of the mudcake at the depth region; determining, using the leak-off rate, the pressure gradient at the depth region; and extrapolating, using the pressure gradient and the size of the build-up zone, to determine the formation pressure.
摘要:
A tubular pipe adapted for transporting oil and water may be treated upon its interior surface to reduce frictional pressure of a multiphase oil/water mixture flowing through the pipe. The tubular pipe may have an interior wall and a central cavity. In some instances, the interior surface is provided with a first textured region being adapted for reducing the adhesive forces of transported oil along the interior wall. A second region upon the interior wall may be adapted for reducing the adhesive forces of water along the interior wall of the tubular pipe. In some applications, riblets may be provided upon the interior pipe wall to further reduce the frictional forces of fluid flowing through the central cavity of the pipe.