- Отрасли: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
A constant provided in an equation that applies only for a particular system of units. This is useful for analysts who must work in different units systems to satisfy local preferences.
Industry:Oil & gas
A continuous length of low-alloy carbon-steel tubing that can be spooled on a reel for transport, then deployed into a wellbore for the placement of fluids or manipulation of tools during workover and well-intervention operations. The process of spooling and straightening a coiled tubing string imparts a high degree of fatigue to the tube material. Therefore, a coiled tubing string should be regarded as a consumable product with a finite service life. Predicting and managing the factors that affect the safe working life of a coiled tubing string are key components of the string-management system necessary for ensuring safe and efficient coiled tubing operations.
Industry:Oil & gas
A connection profile used in pipe work and associated equipment to provide a means of assembling and disassembling components. Most oilfield flanges feature a bolt-hole pattern to allow the joint to be secured and a gasket profile to ensure a pressure-tight seal. The design and specification of a flange relates to the size and pressure capacity of the equipment to which it is fitted.
Industry:Oil & gas
A condition whereby the interface of two fluids, such as oil and water, bypasses sections of reservoir as it moves along, creating an uneven, or fingered, profile. Fingering is a relatively common condition in reservoirs with water-injection wells. The result of fingering is an inefficient sweeping action that can bypass significant volumes of recoverable oil and, in severe cases, an early breakthrough of water into adjacent production wellbores.
Industry:Oil & gas
A condition that results when the flow rate varies appreciably during a test period. This can be contrasted to multirate conditions, which describe the step changes in rate demanded by certain test designs. The variable rates observed during drawdown can be measured by a flowmeter at the sandface level in the well. Elegant mathematical methods have been developed to analyze well tests conducted at variable rates. <br><br>Although, from a practical standpoint, it is much more desirable to conduct constant-rate tests, in reality the only truly constant rate is zero. Sandface flow-rate measurements provide considerable information from drawdown data that cannot be learned from a buildup.
Industry:Oil & gas
A condition that occurs when the solids carried in a treatment fluid, such as proppant in a fracture fluid, create a bridge across the perforations or similar restricted flow area. This creates a sudden and significant restriction to fluid flow that causes a rapid rise in pump pressure.
Industry:Oil & gas
A condition that may occur when a coiled tubing string is run into a horizontal or highly deviated wellbore. Lock-up occurs when the frictional force encountered by the string running on the wellbore tubular reaches a critical point. Although more tubing may be injected into the wellbore, the end of the tool string cannot be moved farther into the wellbore.
Industry:Oil & gas
A condition that may occur during ball diversion treatments in which all open perforations capable of receiving fluid are sealed. Ballout is signified by a rapid increase in treating pressure. Maintaining the treatment pressure may result in the breakdown and subsequent treatment of plugged perforations. If no further injection is possible, the pressure must be released to unseat the ball sealers, at which time the treatment will be terminated.
Industry:Oil & gas
A condition in downhole pumping operations that occurs when the stroke length at the subsurface sucker-rod pump is longer than the surface stroke length (polished rod). This phenomenon is caused by the elongation of the rod string because of dynamic loads imposed by the pumping cycle. <br><br>In this situation, when the upstroke begins at the surface, the downhole pump maybe still be moving downward; when the downstroke begins, the downhole pump is still moving upward.
Industry:Oil & gas
A condition in pumping and processing equipment caused by the induction of free gas. The compressible gas interferes with the proper operation of valves and other pump components, preventing the intake of fluid.
Industry:Oil & gas
