Impacts of lithological characteristics, facies and sedimentary environments on the reservoir quality in G sequences, Lac Da Xanh structure, Block 15-1/05, Cuu Long basin
Abstract
The presence of sedimentary rocks of G sequences in the LDX structure in Block 15-1/05, Cuu Long basin is a new discovery compared to previous studies on the geology and petroleum system in Block 15-1/05. The G sequences formations are temporarily named the Lac Da Vang formation, which is covered by Lac Da Nau formation (E sequences) and overlaid on granitoid and andesite - basalt intrusive of pre-Tertiary basement rocks.
The studies on petrography, core and geophysical data of wells LDX-1X, LDX-2X and LDX-3X show that the G sedimentary rocks include interbeds of sandstone, siltstone, claystone/shale, and sedimentary rocks deposited in the alluvial fan, fan delta, braided fluvial and lacustrine environments. The reservoir quality of sedimentary rocks of G sequences is poor, due to the impact of the strong development of secondary minerals along with the burial compression process.
References
PVEP POC, “Potential of clastic basement G sequence in Lac Da Vang discovery based on study of its characterization, Block 15-1/05, offshore Vietnam”, 2012.
PVEP POC, “Integration of characteristics of fault and fracture study in basement of Block 15-1/05, offshore Vietnam”, 2012.
Tập đoàn Dầu khí Việt Nam, Địa chất và Tài nguyên Dầu khí Việt Nam. Nhà xuất bản Khoa học và Kỹ thuật, 2019.
VPI, "Petrography report, 15-1/05-LDV-1X well", 2010.
Robert L. Folk, Petrology of sedimentary rocks. Hemphill Publishing Company, Texas, 1980.
VPI, "Petrography report, 15-1/05-LDV-3X well", 2011.
VPI, "Petrography report, 15-1/05-LDV-2X well", 2011.
Richard H. Worden and Sadoon Morad, Clay mineral cements in sandstones. Wiley-Blackwell, 2003. DOI: 10.1002/9781444304336.
D.W. Houseknecht, “Assessing the relative importance of compaction processes and cementation to reduction of porosity in sandstones”, American Association of Petroleum Geologist Bulletin, Vol. 71, No. 6, pp. 633 - 642, 1987.
Peter A. Scholle and Darwin Spearing, Sandstone depositional environments. American Association of Petroleum Geologists, 1982. DOI: 10.1306/M31424.
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