The Study Of Pre-stack Seismic Inversion Technology For Deep Water Turbidite

In recent years,the exploration and development of oil and gas in the world has been expanding to deep-sea areas,and many important breakthroughs have been made.Slope fans,basin floor fans and low wedge deposits are the key points in the exploration of deep-sea areas at present.Deep-water turbidite often accompanied by salt diapir,mud diapir,thrust anticline and other structures,resulting in the complex and changeable geometry and strong heterogeneity of such reservoirs,and the spatial distribution characteristics,lithology,physical properties and hydrocarbon-bearing characteristics of reservoirs are extremely complex.The development cost of offshore oilfields is higher than that of onshore oilfields,so it is urgent to improve the success rate of exploration and development and reduce the cost.Therefore,it is of great significance to study reservoir prediction and physical property parameter description technology of deepwater turbidite.Inversion of reservoir physical parameters by seismic data is an important subject in seismic data application.In theory,pre-stack gather data hide some information related to lithology,physical property and hydrocarbon-bearing property of underground strata.Using pre-stack CRP gather data and seismic inversion technology,the lithology,physical property and fluid properties of underground reservoirs can be predicted.Therefore,it is very important to carry out pre stack seismic inversion technology and its application for deep water turbidite reservoir.The research work is mainly aimed at a block of Rio Muni Basin in Equatorial Guinea.Aiming at the disadvantageous factors such as complex sedimentary environment,fast change of reservoir lithology and physical properties,the key technologies of reservoir prediction and hydrocarbon detection of deep water turbidite are formed by means of logging curve pretreatment,petrophysical analysis,AVO forward simulation and pre-stack lithologic physical fluid inversion.The main technical difficulties in prestack inversion of deep-water turbidite reservoirs are the selection of sensitive rock physical parameters and the construction of initial models.Using target correlation method to construct elastic parameter technology effectively solves the problem of lacking sensitive parameters of rock physics.The lithology factor,physical factor and fluid factor constructed are the lithology,physical property and fluid sensitive parameters of the target formation in the study area respectively,and can effectively identify high-quality reservoirs and oil layers.Fine horizon interpretation is the key point to solve the technical problem of establishing inversion initial model.Finally,the initial model conforming to the geological law of the study area is obtained.Prestack simultaneous inversion is the key technology of reservoir prediction and hydrocarbon detection in this area.Its application effect is obvious.The inversion profile of lithologic and physical fluids has high signal-to-noise ratio,high vertical coincidence with wells,and lateral distribution conforms to geological knowledge.It is the main basis for sand body tracing,gas reservoir interpretation and target evaluation.