Oil & Gas of Kazakhstan (Kazakhstan)
- Seismic surveys to explore oil and gas deposits were started in the last years at oil prospective areas of the republic, in particular, within the Alakol Lake basin of Almaty and the Eastern Kazakhstan Oblast and in the Karaganda and Akmola Oblasts. How do you assess the prospects of the given operations at the above-mentioned localities?
The greater part of it is located in the Republic of Kazakhstan, while the south-eastern part of it in China. According to geological and geophysical data, the Zaisan Depression has a complicated internal structure, caused by thrust faults and thrusts along the sides of the crystal Paleozoic sediments, and is divided into three structural zones: north-eastern, south-western and central. The Central zone is highly regarded for the discovery of oil- and gas-bearing formations. It is characterized by a deeper bedding of the folded Paleozoic foundation, with a thickness of sedimentary stratum up to 5 kilometers. The systematic exploration of the Zaisan Depression was started in the fifties. At that time, about 40 non-deep wells were drilled along a few anticlinal lines. In 1960, the Dairovskaya key well was drilled to the depth of 1,686 m., where no productive deposits were discovered. In 1982-1988, more than 4,000 kilometers of seismic profiles were traversed. In 1988, the Sarybulak-1 well was drilled, where oil was discovered at the depth of 3,000 m. in the Permian sand rock. In December 1997, Kuat (currently Tarbagatay Munay LLP) entered into a contract with the Kazakhstan government for exploration and production of hydrocarbons on the licensed area within the Zaisan Depression. The subsoil user conducted a 2D seismic survey of 516 linear meters and 3D seismic survey of 474 square kilometers in the eastern part of the Zaisan Depression. The last years’ 2D seismic survey data on 2,245 linear meters were processed and interpreted. In 2002-2003, the Karabulak-1 and Sarybulak-2 wells were drilled at the contracted area. While testing the second of the above-mentioned wells, a commercial flow of dry gas came out from the Lower Palaeogene Era sediments, and highly-viscous heavy resinous crude oil was produced from the Upper Permian Period sediments. The Preliminary estimate of commercial gas reserves, based on data on the first exploratory well, Sarybulak-2, is 27.6 billion cubic meters. Probable recoverable gas reserves are 60-70 billion cubic meters. The Sarybulak-3-G well was drilled in 2005. Gas withdrawal took place with the flow rate of 271.9 thousand to 335.3 thousand cubic meters per day. Exploratory operations will continue in 2007. The following activities are scheduled: 2D seismic survey of 170 linear kilometers, drilling, testing of three wells, and simulation of the geological structure of the Sarybulak geological formation. The Alakol basin area is a geological and geographical extension of the Dzungarian oil-and-gas bearing basin of China in Kazakhstan. The analysis of materials studying the Northern Dzungarian region allow us to consider the Dzungarian and Alakol depressions as two giant reservoirs, linking to each other by a tectonic passage, called the Dzungarian Gates. The most favorable conditions for formation of oil and gas were in the Permian Period, a period when volcanic activity activated in this region. Despite insufficient study of this area, many observations give evidence of the high probability of oil-and-gas occurrence at the Kazakhstan part of the Northern Dzungaria. To the north from the main Dzungarian fracture under supposed thrust, within the Gaity River basin the veins of asphalt types in limestone, abundantly impregnated with bitumen were discovered. On the opinion of the majority of researchers, the most promising area for the initial hydrocarbons exploration stage is the graben of the Dzungarian Gates. Admittedly, the maximum depth of the graben is located within the southern boundaries of the Dzungarian Gates, reaching 3,000 meters. On the opinion of geologists, at this depth there can be discovered hydrocarbon-containing sediments of the Jurassic Period. Geological survey operations within the Alakol depression have only just been started this year. The Remas Company carried out an offshore magnetic survey of 380 linear kilometers in the Alakol Lake basin. A 2D seismic survey was conducted both onshore and offshore. Over 400 linear kilometers onshore and over 55 linear kilometers offshore were drilled. Currently, the filed study material is being simultaneously processed and interpreted. Geochemical sampling was made within the area of occurrence of source rock and in the area of hydro geological wells. In one of the wells a hydrocarbon skim was discovered on the eastern shore of the Alakol Lake. From 1996-2003, Azimut Energy Services OJSC carried out a seismic survey within the eastern and south-eastern parts of the Tenyz Depression with the purpose of accessing the given territory for the prospect of the occurrence of oil and gas. Based on the work results, three promising sites were defined in the south-eastern part of the depression. The most promising of them is Muzbel’. Despite the high expectations of the occurrence of oil and gas in the south-eastern part of the Tenyz Depression, no deep well was drilled in the given area, and thus no sufficient data is available on physical features of potential reservoirs. In 2003, a detailed seismic survey was carried out along seismic profiles at Muzbel’, the frequency of which allowed the fixing of a spot for drilling a deep exploratory parametric well. Drilling of the 1-P well with the target depth of 4,000 meters has been started in 2007 at Muzbel’ in the south-eastern part of the Tenyz Depression, financed from budget funds.
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