- 行业: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
A coil in an induction logging tool designed to buck out, or reduce, the direct coupling between transmitter and receiver coils. The direct coupling signal is far larger than the formation signal. The bucking coil is wound with the opposite polarity to the main receiver coil, and placed in series with it at a location that minimizes the direct coupling. The combination of transmitter, main receiver and bucking coils is known as a mutually balanced array.
Industry:Oil & gas
A classification of blowout preventer in which the pressure-control functions are achieved through the operation of hydraulically operated ram sets. Each ram set is configured as an opposing pair and, depending on function, are designed to close within the bore of the preventer. Ram preventers are commonly available in single-, double-, triple- and quad-ram configurations.
Industry:Oil & gas
A class of high-performance thread types that are commonly used in modern oilwell and gaswell completions. Premium threads are available in a number of configurations and are typically designed to provide superior hydraulic sealing, improved tensile capacity and ease of make-up. Unlike conventional threads, the sealing areas in premium thread connections are independent of the thread profile and are included as two or three areas within the tool joint, thereby providing some redundancy.
Industry:Oil & gas
A chemical used to break emulsions to determine the total amount of sediment and water in the samples.
Industry:Oil & gas
A Christmas tree design for subsea applications, configured with the master valves and flow-control equipment on a horizontal axis to minimize the assembly height.
Industry:Oil & gas
A chemical used to bind metal ions to form a ring structure. Chelating agents stabilize or prevent the precipitation of damaging compounds. In the oil field, chelating agents are used in stimulation treatments and for cleaning surface facilities. They are also used to treat or remove scale or weighting agents in reservoir drilling fluids. <br>During acid or scale-removal treatments, various compounds may be dissolved in the treatment fluid. As the acid reacts and the pH increases, reaction products may precipitate as a gelatinous, insoluble mass. Should this occur within the formation matrix, it is almost impossible to remove and permanent permeability damage may occur. Chelating agents prevent precipitation by keeping ions in a soluble form until the treatment fluid can be flowed back from the formation during cleanup. <br>Typical oilfield chelating agents include EDTA (ethylenediamine tetraacetic acid), HEDTA (hydroxyethylenediamine triacetic acid), NTA (nitriolotriacetic acid) and citric acid.
Industry:Oil & gas
A chemical injected into the wellbore to prevent or minimize paraffin deposition. The effectiveness of paraffin inhibitors is strongly dependent on crude oil composition. <br><br>Paraffin inhibitors must be introduced into the oil before the oil cools to its cloud point. In additional, asphaltene composition should be determined before treatment because it can reduce the effectiveness of the paraffin inhibitor. In some cases, the use of a paraffin inhibitor can actually increase the rate of paraffin deposition because the stability of colloidal asphaltenes is disturbed.
Industry:Oil & gas
A chemical or fluid that alters the performance of an engineered slurry or treatment fluid. Some remedial cementing treatments require unpredictable volumes of cement slurry to achieve the desired results. When excess slurry is left in the wellbore, it may not be possible to remove the excess slurry by conventional means, such as reverse circulation, before the slurry thickens and becomes immovable. Mixing the contaminant with the slurry in the correct proportions increases the thickening time of the slurry, allowing it to be safely removed from the wellbore.
Industry:Oil & gas
A chemical agent used to increase the thickening time of cement slurries to enable proper placement. The need for cement retardation increases with depth due to the greater time required to complete the cementing operation and the effect of increased temperature on the cement-setting process.
Industry:Oil & gas
A chemical agent used in stimulation treatments to ensure uniform injection over the area to be treated. Chemical diverters function by creating a temporary blocking effect that is safely cleaned up following the treatment, enabling enhanced productivity throughout the treated interval. <br><br>In matrix acidizing of injection wells, benzoic acid is used as a chemical diverter, while oil-soluble resins are employed in production wells. Both compounds are slightly soluble or inert in the acidic medium (HCl), but after functioning as diverters, they dissolve with water injection or oil production, respectively. Stable, viscous foams generated in the rock matrix are also considered to be chemical diverters.
Industry:Oil & gas
