Petroleum exploration wells

Even if all of the elements described so far have been present within a sedimentary basin an accumulation will not necessarily be encountered. One of the crucial questions in prospect evaluation is about the timing of events. The deformation of strata into a suitable trap has to precede the maturation and migration of petroleum. The reservoir seal must have been intact throughout geologic time. If a leak occurred sometime in the past, the exploration well will only encounter small amounts of residual hydrocarbons. Conversely, a seal such as a fault may have developed early on in the field s history and prevented the migration of hydrocarbons into the structure. 

Oil production starts with petroleum exploration. Oil geologists study rock formations on and below the Earth s surface to determine where petroleum might be found. The next step is preparing and drilling an oil well. After completing the well, which means bringing the well into production, petroleum is recovered in much the same way as underground water is obtained. 

The ethyl alcohol fermentation is of course an age-old process and is so well known that little need be said about it here. The acetone-butanol fermentation is perhaps the next most important industrial fermentation process, although starch in the form of maize has been largely used as the basic material more recently suitably treated molasses has been used. The fermentation, a relatively rapid process requiring about thirty hours, produces about 60 parts of butanol, 30 parts of acetone and 10 parts of ethyl alcohol. These products already have large uses in industry and other uses are being explored. One possibility is the use of butanol in motor fuel. Jean has described a fuel, called Jeanite, consisting mainly of butanol and ethyl alcohol, which shows some promise. Of course the admixture of ethyl alcohol with petroleum is well known and an increased use of this mixture is probable. 

In offshore operations, exploration wells are almost always plugged and abandoned even when they strike petroleum. Their sole function is to find oil or gas and to delineate the reservoir. The operator uses this information to pick a location for a permanent production platform from which development wells will be drilled to recover as much petroleum as economically possible. In onshore operations, however, successful exploration wells also become producers. 

BNL, Halliburton Energy Services, and Unocal Corp. have developed cements suitable for geothermal wells with this formulation [11]. The brand name of this cement is ThermaLock. This cement was tested successfully in Unocal s geothermal well in Sumatra, Indonesia, and its first use has been reported by Japan Petroleum Exploration Company for completion of geothermal wells in Kyushu, Japan. 

Significant oil spills have also occurred from offshore drilling or production platforms as the result of mechanical or operational failure, hi 1979 the IXTOC-I exploration well had an uncontrolled blowout that spilled more than 551,000 tons (500,000 metric tons) of petroleum into the Gulf of Mexico. Smaller spills include one that occurred in 1969 off Santa Barbara in southern California, when about 11,000 tons (10,000 metric tons) were discharged, and the Ekojisk blowout in 1977 in the North Sea off Norway, which totaled 33,000 tons (30,000 metric tons) of crude oU. 

Petroleum exploration and production activities are performed primarily by geologists, geophysicists, and engineers. Geologists look for areas of the earth where sediments accumulate. They then examine the area of interest more closely to determine whether or not source rocks and reservoir rocks exist there. They examine the rocks at the surface of the earth and information from wells drilled in the area. Geologists also examine satellite images of large or remote areas to evaluate the rocks more quickly. 

Once a successful exploration well has been drilled, the oil and/or gas flow are pumped to the surface of the earth through the well. At the surface, the petroleum either moves through a pipeline or is stored in a tank or on a ship until it can be sold. 

Petroleum exploration specialists are using a type of geophysical data known as three-dimensional seismic data to study the structures and rock types below the surface of the earth in order to determine where exploration wells might successfully produce petroleum. Geochemists are assessing the results of studies of the chemistry of the surface of the earth and whether or not these results can improve the predictions of scientists prior to drilling expensive exploratory wells. 

Under Subtitle C of the Resource Conservation and Recovery Act (RCRA), certain wastes containing designated TPH compounds and petroleum-related industrial wastes are listed as hazardous. However, RCRA excludes some TPH-related wastes from regulations (e.g., certain exploration, well development, and productions wastes). The RCRA-listed wastes are also controlled under the Comprehensive Environmental, Response, Compensation, and Liability Act (CERCLA) for accidental releases to the environment. 

Wang, D.-C., Yang, T.-R., Du, T.-R, Fang, B.-F., Yang, C.-Z., 1999a. Micellar/polymer flooding pilot test in the HI84 well pattern in the Laojunmiao field. Petroleum Exploration and Development 26 (1), 47-49. 

The numerous outcrops, the tunnels and the extensively cored petroleum, water and geothermal exploration wells make the Swiss Molasse basin an ideal candidate for such a study by providing the opportunity to develop the necessary regional sedi-mentological framework and allowing detailed sampling in the wells and tunnels to study diagenesis in the subsurface. 

The oil and gas industry of Kuwait is subordinated to Kuwait Petroleum Corporation (KPC). Its structure includes five companies. (1) Kuwait Oil Corporation (KOC) looks at both the production and export of petroleum and gas. (2) Kuwait National Petroleum Company looks after oil processing and manufacture of liquified natural gas, as well as their marketing and export. (3) Petrochemical Industries Company (PIC) is engaged in the manufacture and export of petrochemical products. (4) Kuwait Oil Tankers (KOTC) engages in the transportation of petroleum, petroleum products and liquefied gas. (5) Kuwait Foreign Petroleum Exploration Company looks at both the extraction of petroleum and gas abroad. In 1998, the Supreme Council of Kuwait accepted the decisions to reorganize the KPC, as well as privatize the PIC and KOTC. 

Takahashi, H., Japan Petroleum Exploration Co., L., Yonezawa, T., Corporation, J.N.O., Takedomi, Y., and Ministry of Economy, T.A.I., 2001. Exploration for Natural Gas Hydrate in Nankai-Trough Wells Offshore Japan, Offshore Technology Conference, Volume 13040 Houston, Texas, OTC. 

In 1995, Japan s Ministry of Economy, Trade and Industry (METI), formerly Ministry of International Trade and Industry (MITI), launched a project to explore for marine gas hydrate accumulations around Japan. From late 1999 to early 2000, an exploratory hole MITI Nankai Trough was drilled on the landward side of the eastern Nankai Trough, offshore Japan (Fig. 1) by Japan National Oil Corporation (JNOC) along with Japan Petroleum Exploration Co., Ltd (JAPEX) as the well operator. The water depth at the drill site was 945 m and the sub-bottom depth of the hole was 2355 m. The seismic bottom simulating reflector (BSR) is present at around 295 mbsf. There were two exploration objectives one was a gas hydrate survey in shallow Quaternary sediments and the other was conventional oil and gas exploration in deeper Tertiary sediments. In addition to the main hole, seven short holes (two site survey, two pilot and three post-survey holes) were also drilled for the gas hydrate survey around the main hole. In this paper, we will clarify the origins of methane in gas hydrates found in the MITI Nankai Trough Well and discuss gas migration and hydrate formation in the sediments. 

Grzybowski described the foraminifera from the Carpathians in a series of monographs and then applied his findings to foraminifera from the Galician oil fields. He was soon able to demonstrate that it was possible to correlate subsurface strata in wells drilled for petroleum exploration using these fossils. The methods pioneered by Grzybowski continue to be used, and the study of microorganisms has been very much centered on the requirements of the petroleum industry. 

Production and Consumption. About 80% of the world s barite production is used as a weighting agent for the muds ckculated in rotary drilling of oil and gas wells (see PETROLEUM, DRILLING FLUIDS AND OTHER OIL RECOVERY CHEMICALS). Table 2 shows the U.S. production—consumption balance. The 1988 demand for barite increased nearly 40% over that recorded in 1987. However, by the end of 1988, oil prices had declined and renewed economic uncertainties depressed exploration and development activity. Barite demand fell accordingly and imports of lower cost foreign product exceeded domestic production. 

Petroleum engineers are traditionally involved in activities known in the oil industry as the front end of the petroleum fuel cycle (petroleum is either liquid or gaseous hydrocarbons derived from natural deposits—reservoirs—in the earth). These front end activities are namely exploration (locating and proving out the new geological provinces with petroleum reservoirs that may be exploited in the future), and development (the systematic drilling, well completion, and production of economically producible reservoirs). Once the raw petroleum fluids (e.g., crude oil and natural gas) have been produced from the earth, the back end of the fuel cycle takes the produced raw petroleum fluids and refines the.se fluids into useful products. 

Producing companies locate the subsurface petroleum resources recover the oil, gas or condensate and then market the recovered resource to customers. These activities involves planning and carrying out exploration, drilling and well completion, and the production activities. 

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