- Industry: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
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The communication tunnel created from the casing or liner into the reservoir formation, through which oil or gas is produced. The most common method uses jet perforating guns equipped with shaped explosive charges. However, other perforating methods include bullet perforating, abrasive jetting or high-pressure fluid jetting.
Industry:Oil & gas
The commingled flow of different phase fluids, such as water, oil and gas. Multiphase fluid flow is a complex factor, important in understanding and optimizing production hydraulics in both oil and gas wells. Four multiphase fluid flow regimes are recognized when describing flow in oil and gas wells, bubble flow, slug flow, transition flow and mist flow.
Industry:Oil & gas
The combination of a deep-induction and a medium-induction array on the same sonde. In a typical implementation, the two arrays share the same transmitters but have different receivers. If the dual-induction log is combined with a shallow laterolog or microresistivity log, it is possible to correct for the effect on invasion on the deep log, assuming a step profile.
Industry:Oil & gas
The collective term for substances added to drilling fluids when drilling fluids are being lost to the formations downhole. Commonly used lost-circulation materials include are fibrous (cedar bark, shredded cane stalks, mineral fiber and hair), flaky (mica flakes and pieces of plastic or cellophane sheeting) or granular (ground and sized limestone or marble, wood, nut hulls, Formica, corncobs and cotton hulls). Laymen have likened lost-circulation materials to the "fix-a-flat" materials for repair of automobile tires.
Industry:Oil & gas
The closeness of the agreement between the result of the measurement and the conventional true value of the quantity. Accuracy should not be confused with precision. (ISO)<br><br>Core measurements have well-defined calibration techniques and standards. Logging measurements are characterized during tool design and construction, and calibrated regularly to some standard. The quoted accuracy of a log then depends on the initial characterization, the reproducibility of the standard, and the stability of the measurement between calibrations and under downhole conditions. The actual accuracy also depends on the equipment performing and being operated to specification.
Industry:Oil & gas
The closeness of agreement between the results obtained by applying a measurement procedure several times on identical materials and under prescribed measurement conditions. The smaller the random part of experimental error, the more precise the measurement procedure. (ISO)<br><br>In logging, the term usually describes the repeatability of a statistical measurement, such as a nuclear log. The precision must then refer to a particular set of conditions, for example, the speed of logging and the formation properties.
Industry:Oil & gas
The closeness of agreement between individual results obtained in the normal and correct operation of the same method on identical test material, but under different test conditions (such as different operators, different apparatus, different laboratories). (ISO)<br><br>The reproducibility of core and log measurements can be checked properly in the laboratory. However, it is difficult to check the reproducibility of downhole log measurements because of the problem of ensuring that the same test material is used, in other words that the same volume of formation is measured each time, or that the formation fluids have not changed.
Industry:Oil & gas
The closeness of agreement between independent results obtained in the normal and correct operation of the same method on identical test material, in a short space of time, and under the same test conditions (such as the same operator, same apparatus, same laboratory). (ISO)<br><br>The repeatability of core and log measurements can be checked properly in the laboratory. The repeatability of a downhole log is checked by recording a repeat section (or repeat stations for stationary measurements). The term repeatability is used even though it is not possible to ensure that the same test material is used. On two separate runs, the tool may not take the same path in the borehole, and therefore may not measure the same volume of formation.
Industry:Oil & gas
The change in oil-water or gas-oil contact profiles as a result of drawdown pressures during production. Cresting occurs in horizontal or highly deviated wells and is affected by the characteristics of the fluids involved and the ratio of horizontal to vertical permeability.
Industry:Oil & gas
The change in oil-water contact or gas-oil contact profiles as a result of drawdown pressures during production. Coning occurs in vertical or slightly deviated wells and is affected by the characteristics of the fluids involved and the ratio of horizontal to vertical permeability.
Industry:Oil & gas
