The Analysis Of The Reservoir Distribution Modes Based On Stratigraphyic Structure

The previous researches on the distribution rules of volcanic reservoir are often about the volcanic lithologies and lithofacies, eruption times and cycles, volcanic stratigraphic units and volcanic edifices. This paper believes the close relationship between volcanic stratigraphic textures and reservoir by the research of Songliao basin. Thus, it is significant for deepening research on volcanic reservoir to definite the the types and features of the volcanic stratigraphic textures and establish the relationship volcanic stratigraphic textures and reservoir. That also could provide the assistance to explore and develop the volcanic oil and gas.This paper apply the rectification the lithology by observing rock core, common slips and casting slips, combined the lithofacies Classification of the seismic data and logging information and determine three volcanic by seismic data and reflection characters. This paper also gets actual measured porosity, types of reservoir space and formation and gas testing and establish the relationship between stratigraphic textures, as the following:In the research parts,the major parts are acid rock in the fault depressions of the Changling and Xujiawezi, and the fault depression of Dehui mainly contain the netural and neutral-acid rock, the fault depression mainly contains the shoshonitic volcanic rocks. They mainly belong to effusive facies and explosive facies. The effusive facies mainly include the hot pyroclastic flow subfacies. The fault depressions of Cahngling and Dehui mainly belong to the lower subfacies and Xujiaweizi’s mainly is the upper subfacies. The volcanic stratigraphic textures could be divided into lamelleted, quasi-lamellar and bulk shapes. The lamelleted volcanic stratigraphic textures are featured by middle-high frequency, middle-strong amplitude and fine continuity. The features of reflection characters mainly include the subparallel reflection configuration, multilevel structure and small thickness of single layer. The top and bottom level show the parallel contactand the lithology mainly belong to be acid and the effusive and explosive facies. Subparallel volcanic stratigraphic textures are featured by middle-high frequency, middle-strong amplitude and fine continuity. Seismic reflection signatute is subparallel seismic reflection configuration. The thickness of lateral strata vary greatly, top and bottom levels skew. The lithology is the acid rock and the lithofacies is effusive. Bulk volcanic stratigraphic textures are featured by middle-low frequency, middle-weak amplitude and bad continuity. Its seismic reflection signatute is disorder or blank seismic reflection configuration. Generally, it often is single-layer structure and the bulk-shape. This kind of rock is dacite and effusive.Dome-shaped- messy reflection seismic facies are mainly dacite. Petrofacies are mainly intrusive facies and explosive facies, the reservoir space is mainly dissolved pores and various types of cracks, and porosities are based on middle-sized pores; hummocky sub- paralleling reflection seismic facies are mainly rhyolite and latites, its petrofacies are mainly effusive facies and explosive facies, and the reservoir space includes gas holes, various types of dissolved pores, dissolution fractures and structural fractures, its porosities are based on middle-sized pores as well.Parallel or sub-parallel reflection seismic facies are mainly rhyolite, the petrofacies are mainly effusive facies and explosive facies, reservoir space is all kinds of pores and cracks and the porosities are mainly high holes; mushroom- messy reflection seismic facies are mainly intermediate-basicvolcanic rocks, its petrofacies are mainly explosive facies and volcanic conduit facies, the reservoir space is all types of pores and cracks, porosities are based on high holes and higher holes.