Authors:
Liangjie Zhang
1
;
Hongjun Wang
1
;
Xingyang Zhang
1
;
Wenxin Ma
2
;
Laiyong Cao
3
and
Hongwei Zhang
1
Affiliations:
1
Petrochina Research Institute of Petroleum Exploration & Development, No. 20, Xueyuan Road, Haidian District and Beijing, China
;
2
CNPC Chuanqing Drilling Engineering Company Limited Geological Exploration & Development Research Institute, No. 3, Section 1, Fuqing Road, Chenghua District, Chengdu and Sichuan Province, China
;
3
CNPC(Turkmenistan) Amu Darya River Gas Company, No. 9, Advance Road, Changping District and Beijing, China
Keyword(s):
The Amu Darya Right Bank, structural style, carbonate reservoir, fracture, natural gas
Abstract:
The Amu Darya Right Bank is located in the northern part of Turkmenistan. Middle-Lower Jurassic coal-bearing deposits, Middle-Upper Jurassic carbonate rocks and Upper Jurassic salt rocks are the major sedimentary assemblages. The east of the right bank is located in the Southwestern Gissar thrust belt, and the reservoir is the most important risk factor. Based on the fault-related folds theory, have analyzed the structural pattern of the thrust - fold belt, figured out their effects on development of fractures and carbonate reservoirs, and influence on natural gas accumulation. The study shows that breakthrough fault-propagation folds and fault-bend folds dominate the east. With structural highs far away from the primary fault, breakthrough fault-propagation folds have abundant fractures, but weak dissolution, where the reservoirs and gas pools are mostly fracture-pore type, the wells have low production, and the water/gas ratio increases with the increase of distance from the primar
y fault. Fault-bend folds have structural highs close to the primary fault, abundant fractures, and strong dissolution by deep hydrothermal fluid, so the reservoirs and gas pools in them are mostly fracture-cave type, with high production of well. After comprehensive analysis, it is suggested to adopt deviated wells on breakthrough fault-propagation folds, and vertical wells on structural highs of fault-bend folds.
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