① 中国石化西南分公司勘探开发研究院德阳分院,四川 德阳 618000;
② 成都理工大学油气藏地质及开发工程国家重点实验室,四川 成都 610059
Analysis on Triassic Xujiahe Stage Second Segment (Tx2) seismic facies and prediction of sedimentary facies
Zhao-Shuang1, Gao Qian2, Qiao Shu-rong1
1. Deyang Branch of Southwest Institute of Exploration and Development, SINOPEC, Deyang City, Sichuan Province, 618000, China;
2. State Key Lab of Reservoir Geology and Development Engineering, Chengdu University of Technology, Chengdu City, Sichuan Province, 610059, China
Abstract：The DY area is new exploration area with relatively complex structure, in which the Xujiahe Stage Second Segment (Tx2) strata was drilled only in the DY-1well. The study on sedimentary facies of the strata was only on the basis of regional knowledge, which is unable to provide reliable sedimentary facies zone for exploration and development and predict favorable reservoir. For that reason, facing the objective strata in the area, the prediction of planar distribution of seismic facies was carried out by using sequence-stratigraphic and seismic-stratigraphic principles, combining with surface outcrops data, regional sedimentary background and predecessors' studied results, taking 3D seismic prestack time migration data as basis and using the tool combining manual interpretation of typical seismic facies sections with planar prediction of software in seismic work station and presented new knowledge on division of sedimentary facies zone by combination of drilling data with logging facies interpretation in DY-1well at the same time. The results proved that the Tx2 strata belongs to delta environment sediment, main sedimentary sub-facies is delta plain and delta front and the reservoir of interest is situated in superimposed distributary channel and mouth bar sand body in the axial part of later structural deformation, which is characterized by tight reservoir but fracture developing. The predicted results coincide with the drilling in the DY area.
