API is the only national trade association that represents all aspects of America’s oil and natural gas industry. API leads the development of petroleum and petrochemical equipment and operating standards. API also certifies inspectors of industry equipment. The development of consensus standards is one of API’s oldest and most successful programs. Beginning with its first standards in 1924, API now maintains some 500 standards covering all segments of the oil and gas industry
A relatively common sedimentary mineral that forms massive rock layers. Anhydrite does not form directly, but is the result of the dewatering of the rock forming mineral Gypsum. This loss of water produces a reduction in volume of the rock layer and can cause the formation of caverns as the rock shrinks
Drilling undertaken to define hydrocarbon volumes and options for development. See also appraisal well
The Natural Gas Index is designed to measure the performance of highly capitalized companies in the natural gas industry involved primarily in natural gas exploration and production and natural gas pipeline transportation and transmission.
A raw, coarse-grained sandstone, deposited very near the rocks that create its sediments. Arkose consists of quartz along with a significant proportion of feldspar, a mineral that usually degrades quickly into clay. Its mineral grains are generally angular rather than smooth and rounded, a sign that they were transported only a short distance from their origin
Clause in a gas sales contract. The amount of gas a buyer agrees to purchase from the seller over the length of a contract year, most accurately expressed in MMBtu, and measured in gross heating. Generally the sum of DCQs in effect throughout the year. The ToP amount will be set as a percentage of the ACQ, typically between 70-80%. (365 x DCQ)
A license given by the licensing authorities to drill an appraisal well
This terminal is the end of the pipeline. Similar to the departure terminal it has a scraper receiver, inlet and outlet valves, and flowmeter and communication subsystems
Aquifers are underground porous, permeable rock formations that act as natural water reservoirs. However, in certain situations, these water containing formations may be reconditioned and used as natural gas storage facilities. As they are more expensive to develop than depleted reservoirs, these types of storage facilities are usually used only in areas where there are no nearby depleted reservoirs. Traditionally, these facilities are operated with a single winter withdrawal period, although they may be used to meet peak load requirements as well. Aquifers are the least desirable and most expensive type of natural gas storage facility for a number of reasons. First, the geological characteristics of aquifer formations are not as thoroughly known, as with depleted reservoirs. A significant amount of time and money goes into discovering the geological characteristics of an aquifer, and determining its suitability as a natural gas storage facility. Seismic testing must be performed, much like is done for the exploration of potential natural gas formations. The area of the formation, the composition and porosity of the formation itself, and the existing formation pressure must all be discovered prior to development of the formation. In addition, the capacity of the reservoir is unknown, and may only be determined once the formation is further developed. In order to develop a natural aquifer into an effective natural gas storage facility, all of the associated infrastructure must also be developed. This includes installation of wells, extraction equipment, pipelines, dehydration facilities, and possibly compression equipment. Since aquifers are naturally full of water, in some instances powerful injection equipment must be used, to allow sufficient injection pressure to push down the resident water and replace it with natural gas. While natural gas being stored in aquifers has already undergone all of its processing, upon extraction from a water bearing aquifer formation the gas typically requires further dehydration prior to transportation, which requires specialized equipment near the wellhead. Aquifer formations do not have the same natural gas retention capabilities as depleted reservoirs. This means that some of the natural gas that is injected escapes from the formation, and must be gathered and extracted by ‘collector’ wells, specifically designed to pick up gas that may escape from the primary aquifer formation. In addition to these considerations, aquifer formations typically require a great deal more ‘cushion gas’ than do depleted reservoirs. Since there is no naturally occurring gas in the formation to begin with, a certain amount of natural gas that is injected will ultimately prove physically unrecoverable. In aquifer formations, cushion gas requirements can be as high as 80 percent of the total gas volume. While it is possible to extract cushion gas from depleted reservoirs, doing so from aquifer formations could have negative effects, including formation damage. As such, most of the cushion gas that is injected into any one aquifer formation may remain unrecoverable, even after the storage facility is shut down.
