Application And Investigation Of Geophysiacl Methods For Sedimentary Reservoir In Sanhu Area

Oil resources is rich in Sanhu area of the east Qaidam Basin, the three major gas fields have been found(Tainan structure, Sebei No.1, Sebei No.2) and a plurality of gas bearing structures, exploration and research for many years showed that biogenic gas in Sanhu area is mainly distributed in the Quaternary, The characteristic of gas on seismic section is obvious,main performance for low frequency, low speed, high amplitude, seismic event "drop down" features, reservoir trap identification technology has become mature, but with the exploration degree increase in Sanhu area, the area is very difficult to find new traps, exploration targets become natural gas replacement of the field to the potential of low amplitude structural traps and lithologic trap.Lithologic exploration has great prospect in sanhu area, the development of a variety of types of depositional systems, laid a solid material foundation for the kinds of lithologic trap formation. As a long-term, continuous biogas lithologic gas reservoir provides a rich gas source supply. Sand permeability good conditions and large area distribution for lithologic gas reservoir accumulation migration channel. But the sanhu area quaternary lithologic gas reservoir in the area also has its own characteristics, characterized by weak diagenesis,relatively high porosity and permeability of lithologic gas reservoir seal condition is relatively poor, lead to large difference of gas saturation in the reservoirs, moreover the thin reservoir thickness(1-3 m), geophysical response characteristics of surrounding rock is small, the lithological exploration and the lack of effective reservoir and gas detection and recognition theory and technology, to bring great difficulty in lithologic gas reservoir exploration, restricts the sanhu area lithologic gas reservoir exploration and the pace of progress.This thesis is based on the study of the regional geology, relying on high precision 2D seismic data and 3D3 C seismic data, sedimentology, sequence stratigraphy and petroleum geology theory as the instruction, by conducting high-fidelity prestack amplitude processing technology research, key research and solve the near surface structure, surface gas on the deep influence of imaging problems, eliminate near-surface influence factors, the implementationof small amplitude structural trap and lithologic structure, strengthen the earthquake information research, optimizing gas detection method, the amplitude difference pre-stack and post-stack gas reservoir prediction technology research, prestack AVO analysis and elastic parameter inversion, and improve the quality of seismic data using to explore lithologic gas reservoir prediction in the area of geophysical technology series.