Characteristics Of Seismic Facies And Distribution Of Intra-platform Beach In The Ordovician Of Ka1 Three Dimensional Seismic Area In Tazhong Region

Nearly thirty years of research, many scholars in the Ordovician Tazhong region of the characteristics of sedimentary facies and lithofacies palaeogeography has done a systematic work, the reservoir and seismic reflection characteristics of ka 1 three dimensional seismic area predecessors have tried, and achieved fruitful research results. But in the Ordovician marine carbonate rocks of Tarim basin exploration and research direction are mainly concentrated in platform edge facies belt, geomorphology and broad platform internal sedimentary facies and the lack of system research, Lead to mechanism of reservoir development and edge facies belt is not clear, restricted the oil and gas exploration into platform inside. This paper depends on the ka 1 three dimensional seismic area in Tazhong region, the sedimentary facies and the ancient geography controlling reservoir development made a preliminary study. Through the detailed interpretation of 3d seismic data and analysis of 7 wells in the area of information, has been clear about the blocks within the Ordovician widely exists intra-platform beach, and try to accurate recognition and prediction intra-platform beach favorable development zone, for Tazhong region further exploration to make reliable guide to the inside platform.The Ordovician is the main exploration target layer in Tazhong region. Since the 80’s on the Tazhong no. 1 fault belt in well TZ-1 get a high yield and good oil and gas shows, Wells TZ-12,TZ-16,TZ-30,TZ-45,TZ-44, successively get breakthrough in the ordovician carbonate rocks, makes Tazhong region made important progress in the ordovician carbonate oil and gas exploration. In recent years, increasing of basin exploration, although a series of achievements have been made, but the Tarim basin reservoir basic geological data are relatively incomplete, hidden deep buried depth(below the average depth of 4000m), such characteristics as complicated construction conditions, always restricts the Tarim basin oil and gas exploration and development. So using measures of the 3d seismic technology, detailed interpretation of seismic data is relatively reliable and can rely on the tools. With the exploration direction gradually toward the platform inside, people have realized the importance of 3d seismic method applied, especially in the case of transverse prediction of sedimentary facies has the incomparable advantage over drilling data.Using the core, drilling data and 3d seismic data, summarizes ka 1 three dimensional seismic area of the Ordovician in intra-platform beach seismic facies characteristics,:Inside has a high frequency of seismic reflection wave, strong or weak amplitude change is obvious, formation thickness has a significant change on the flanks, and adjacent formation lithology has obvious difference; External shape on top and bottom with wide, slow lenticular or mounded shape, the surrounding rock near intra-platform beach, is obviously overlap or lie on the beach, that sedimentary environment has the obvious change at that time. In explaining the blocks on the basis of 3d seismic data Extract seismic attributes, using seismic stratigraphic thickness, reduction of tectonic geomorphology, ka 1 three dimensional seismic area of the Ordovician in intra-platform beach development zone to the precise identification. Tazhong region in the Ordovician widely exists intra-platform beach, Tazhong region of oil and gas exploration in the future has a positive guiding significance.