Control modes of multitype strike-slip fault systems on fractured-vuggy carbonate reservoir development

Fractured-vuggy carbonate hydrocarbon accumulations are the main reservoirs type in Ordovician formation in Tazhong oil field of Tarim basin and many high-productivity wells have been discovered. Years of hydrocarbon exploration here proves that strike-slip fault systems play an important role in controlling development of fractured-vuggy carbonate reservoir and hydrocarbon migration. After systematic study about strike-slip fault systems, it is thought that three strike-slip fault systems mainly developed here, including transtensional type, transpressional type and “X” type. Transtensional type is most in favor of forming fractured-vuggy carbonate reservoir and hydrocarbon migration. Also, we firstly recognize two kinds of typical transpressional-type sinistral strike-slip faults, which are characterized by obvious segmentation in strike direction. Local faults developed within each segment frequently show flower structures in profile, and show a variety of combined styles such as linear horst and graben, en-echelon normal faults, pull-apart graben, horse tail faults on the plane. Study also reveals that cave carbonate reservoir mainly developed within influence range of the large scale strike-slip fault systems. Development degree of cave reservoir and oil and gas enrichment degree are very different in each segment along strike of strike-slip fault. In principal displacement zone, oil and gas is not easy to accumulate and protect. However, oil and gas is frequently rich in terminal zone of the strike-slip faults due to that minor faults most developed here characterized by combination styles of en-echelon normal faults, pull-apart graben and horse tail faults often result in formation of cave reservoir. Presentation Date: Wednesday, October 19, 2016 Start Time: 11:35:00 AM Location: 170/172 Presentation Type: ORAL