The Techniques Of Comprehensive Seismic Analysis In Prediction Of Fractured Carbonate Reservoir In Southern Tahe

With the development of global oil and gas Exploration and Production, the percentage of fractured carbonate reservoirs among hydrocarbon resources increases every year. The fractured carbonate reservoirs have attracted a great deal of attention for the petroleum exploration geologists and geophysicists. The azimuth and density features of the underground fractures are of greatest importance to the exploration of such reservoirs. Coring and well log data have traditionally used in such studies to detect fractures. But the results are reasonable only around some well locations. The azimuth feature of inter-well fractures has therefore to rely on other geological survey means. As seismic data has wider covering area than well log data, the study of parameters of the fracture feature is a new quantitative calculation method with a powerful applicability. The fractures exist in fissured rock can cause physical and chemical properties of the media vary in every direction. It is called anisotropy in seismic exploration. The differences of all kinds of seismic attributes along and perpendicular to the strike of fracture are studied for detecting the fracture. A lot of techniques such as S wave splitting, AVO, AVA, VVA and AVOA were developed and a number of successful examples were reported by the international petroleum industry in recent years.In this thesis, the characteristics and technical difficulties in fractured carbonate reservoir were simulated by some elaborate models. The pre-stack and post-stack seismic responses of fractured carbonate reservoir were studied to set up a typical, practical and efficient technical process for the prediction of the fractured carbonate reservoir. The patterns recognition and controlling factors of fractured carbonate reservoir were summarized. A comprehensive analysis of the Ordovician fractured carbonate reservoir was finished after the fracture prediction. The results produced by all the methods were studied to analyze underground development characteristics and plane spread rule of the fractures.A practical process is launched to predict the multi-scale fractured carbonate reservoir. A number of key methods and techniques including discontinuity analysis, spectrum analysis, curvature analysis, P wave pre-stack anisotropy were adopted to detect the structural fracture, fracture and fault zone. Comparing the prediction results by other compounding application of many techniques, a good match is found between them. The fractured and expanding corrosion zone of target survey areas were predicted successfully. It is shown that the results were highly consistent with actual drilling reports.