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Schlumberger Limited
Industry: Oil & gas
Number of terms: 8814
Number of blossaries: 0
Company Profile:
A downhole tool incorporating a blade assembly that is used to remove scale and debris from the internal surface of a casing string. Generally run on tubing or drillpipe, casing scrapers are routinely used during workover operations to ensure that the wellbore is clean before reinstalling the completion string.
Industry:Oil & gas
A downhole tool frequently used in slickline or coiled tubing tool assemblies to confirm or correlate the tool position on depth-sensitive applications. With the end of the production tubing as a known reference point, any error in measurement that may occur in reaching the treatment depth will be significantly less than what may have resulted if measuring from surface.
Industry:Oil & gas
A downhole tool designed to allow the lower and upper tool-string sections to be parted to enable retrieval of the running string. Hydraulic disconnects rely on the application of a predefined pressure through the running string to activate a release mechanism. In some cases, a ball or dart is plugged to block circulation through the tool string and enable the application of the release pressure.
Industry:Oil & gas
A downhole safety valve that is operated from surface facilities through a control line strapped to the external surface of the production tubing. Two basic types of SCSSV are common: wireline retrievable, whereby the principal safety-valve components can be run and retrieved on slickline, and tubing retrievable, in which the entire safety-valve assembly is installed with the tubing string. The control system operates in a fail-safe mode, with hydraulic control pressure used to hold open a ball or flapper assembly that will close if the control pressure is lost.
Industry:Oil & gas
A downhole safety valve designed to close automatically in an emergency situation. There are two basic operating mechanisms: valves operated by an increase in fluid flow and valves operated by a decrease in ambient pressure. Given the difficulties in testing or confirming the efficiency of these valves, surface-controlled safety valves are much more common.
Industry:Oil & gas
A downhole milling tool designed with an extended pilot or central stinger section that is inserted in the bore of the packer, tubular or equipment being milled. This design helps ensure that the mill follows the desired path and does not damage the casing or liner wall as the milling operation progresses.
Industry:Oil & gas
A downhole lock device, run on slickline, that incorporates a slip mechanism that engages on the tubing wall to anchor the lock at the desired setting depth. Slip locks are not depth-dependent and do not require special completion equipment. However, the slip lock has limited function and pressure capacity and is generally less desirable than nipple or collar locks.
Industry:Oil & gas
A downhole device, usually run on slickline, used to remove sand or debris from the bottom of the wellbore. In operation, an atmospheric chamber within the tool is opened to create a surge of fluids into the chamber. Debris is then held within the chamber for recovery at surface.
Industry:Oil & gas
A downhole device, run and retrieved on slickline, that is placed and anchored within the tubing string to provide a setting point for flow-control equipment such as valves, chokes and plugs. The three main types of lock use different means of locating and securing: a slip lock locates and anchors anywhere within the correct size of tubing; the collar lock locates in the space within tubing collars; and the nipple lock locates within completion nipple profiles.
Industry:Oil & gas
A downhole device used to control fluid flow under downhole conditions. Downhole chokes are generally removable with slickline intervention and are located in a landing nipple in the tubing string.
Industry:Oil & gas