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Geoscience ›› 2023, Vol. 37 ›› Issue (02): 283-295.DOI: 10.19657/j.geoscience.1000-8527.2022.058

• Structural Geology • Previous Articles     Next Articles

Development Characteristics and Evolution Model of F19 Fault in Fuman Oilfield, Tarim Basin

ZHANG Yintao1(), CHEN Shi2,3(), LIU Qiang1, FENG Guang4, XIE Zhou1, LIANG Xinxin2,3, LI Ting1, SONG Xingguo2,3, KANG Pengfei1, PENG Zijun1   

  1. 1. Research Institute of Petroleum Exploration and Development, PetroChina Tarim Oilfield Company, Korla,Xinjiang 841000, China
    2. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China
    3. Basin and Reservoir Research Center, China University of Petroleum (Beijing), Beijing 102249, China
    4. Tazhong Oil and Gas Production Management Area, PetroChina Tarim Oilfield Company, Korla,Xinjiang 841000, China
  • Received:2022-04-11 Revised:2022-07-26 Online:2023-04-10 Published:2023-05-23
  • Contact: CHEN Shi

Abstract:

At present, the Fuman oilfield is a hot area for oil and gas development of fault-controlled fracture-cave reservoirs in the Tarim basin. F19 fault zone belongs to a current key reservoir-increasing area, but the development characteristics and formation mechanism of the faults are unclear. By using various seismic attributes, such as coherence, maximum likelihood and reservoir amplitude change rate, the newly acquired and processed three-dimensional seismic data are accurately interpreted, the development characteristics of fault profile are determined, and the spatial fault structural distribution is characterized. Based on the vertical stratigraphic displacement and the fault zone width, the fault activity intensity is inferred. Combined with the characteristics of fault deformation and the activity patterns of the peripheral orogenic belts, the fault evolution stages are analyzed and the fault development model is established. Superimposing the reservoir development characteristics and the fault distribution patterns, the fault controlling effect on the reservoir is preliminarily analyzed. The study shows that the fault has remarkable plane segmentation characteristics, which can be roughly divided into three segments (north, middle, and south) according to strike variation, and into the lower structural layer (below T∈3), the middle structural layer (T∈3-TO3t) and the upper structural layer (above TO3t) according to the fault deformation characteristics. The fault formation and evolution are multistage, and the F19 fault evolution comprises roughly of three stages: Early Caledonian (late Middle Cambrian), Middle Caledonian (Ordovician) and Late Caledonian (Silurian), among which the Middle Caledonian stage is the most active stage. The reservoir plane is mainly distributed in the strike-slip fault zone, with major differences in the reservoir development strength along the F19 fault strike. It weakens gradually from south to north, which is related to the faulting intensity. Affected by the multistage Middle Caledonian faulting, the Ordovician carbonate reservoir distribution is featured by vertical multi-layer distribution. Under the joint influence of Tabei and Tazhong fault systems, the local maximum principal stress in the Early Caledonian may have deflected counterclockwise from south to north, and gradually transferred from NNE to near NS. Two groups of X-type small-angle intersecting faults were developed, which established the local distribution pattern of F19 fault.

Key words: Tarim basin, Fuman oilfield, F19 fault, multistage evolution, formation mechanism

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