Oil and Gas Potential

The oil and gas potential of the area has been summarized by Alikhanov (1964, 1978), Maksimov (1987) and Meyerhoff (1982).

The presence of seeps and mud volcanoes first attracted attention to the area of Cheleken Peninsula and adjacent offshore areas at an early date. The Cheleken structure is 15 km wide and 45 km long. Wells were drilled at Cheleken to depths of 160 to 170 m in the Upper Pliocene sandstones, from 1907 to 1912. From 1948 through 1957, the field was extended east and west. Three structures were drilled [Zapadno (West) Cheleken (in 1950), Dagadzhik (in 1955), and Aligul (in 1957)] to the Middle Pliocene zones at depths of 958 to 962 m and 2,100 to 2,500 m. Deeper Miocene production was established later. To date, approximately 28 fields have been found in Western Turkmenistan, four offshore and 24 onshore (see Figure 7-32). Production is primarily from Pliocene deposits (depths of 350 to 4,600 m). The exploration effort resulted in the discovery of two giant fields: Cheleken and Kotur-Tepe. The Cheleken Field has estimated 640 million bbl of recoverable oil reserves and 1 TCF of gas, which was mostly flared. The Cheleken Field produced 9,500 Bopd in 1988.

The Kotur-Tepe Field is located on the continuation of the Apsheron-Pre-Balkhan anticlinal trend on the Cheleken Peninsula (Figure 7-36). The Upper and Lower Red-Bed Series, Akchagylian and Apsheronian deposits are the main producing zones. The reservoir rocks are sandstones and siltstones. At least, seventeen units are productive in the eastern part of the field. Porosity ranges from 18% to 29% and permeability varies from 40 to 1,600 mD. The Kotur-Tepe Field has estimated ultimate recovery of 4 Bbbl of oil and 2.1 Tcf of gas.

The oils from the Upper Neogene reservoirs are paraffinic-naph-thenic in composition (Danchenko et al., 1982). They have low density and low resin content.

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