Integrated Research On 3D Seismic Of Offshore Oil And Gas Fields

With the extensive development of offshore oil and gas fields,it is important to exploit the potential zones of existing oil and gas favorable areas.Limited offshore drillings and skewed distribution result in the lack of well logging data and geological data of offshore,which makes it impossible to accurately describe the space distribution of reservoirs and to effectively discriminate the infilled fluid between wells.Fortunately seismic exploration is a technology that can help to reproduce the three-dimensional distribution of target geological bodies.Seismic data processing,inversion and interpretation were always done by different departments of a company or by different companies in the past.Besides,the information of seismic data,well logging data,geology and reservoirs was separate and independent.As a result,the early seismic technology can only be applied to the structural analysis,which is difficult to meet the requirement of reservoir description.Internationally,in order to meet the needs of reservoir exploration,plenty of money was invested in to change the seismic acquisition mode,which includes inter well seismic,VSP,time delayed seismic,multi-wave and high precision 3D seismic acquisition etc.Combined with the new techniques of processing,interpretation and inversion,remarkable benefits in some oil and gas field could be achieved.However,the development of seismic technology itself is not universal.It is not suitable for the development of complex fault block and multilayered oil and gas field in our country.Therefore,in this thesis I focus on the existing three-dimensional seismic data,integrate seismic data,well logging data,geology,reservoir,core and other information to further explore the potential reservoirs.Through the consolidation study of seismic data processing and inversion,the reservoir description accuracy and small fault identification ability can be improved,which provides information support for the adjustment of oil and gas field development plan.This thesis is based on the characteristics of offshore oil and gas fields.Relying on the application of new geophysical technologies and the idea of integrated research,the integration technology of processing,inversion and reservoir study was established.The main research contents include:1.For the reservoir,high fidelity and high resolution processing technology: Based on the well logging and geological data,the seismic data of the target reservoir is processed by zero phase processing;Well controlled high fidelity is uses to remove the multiple wave;Combination of well and seismic is applied to improve resolution;Use advanced high precision tomography inversion and anisotropic depth migration technique to obtain more accurate three-dimensional velocity and migration imaging results.2.For the reservoir,forward modeling and analysis: According to the well logging and seismic data of the target reservoir,a large number of different parameters of the model are set up to meet the geological conditions of the target.In theory,the geophysical response of all kinds of situations is forward modeled,so as to obtain the limit understanding of the thin reservoir and small fault of the target.3.Inversion and analysis of reservoir parameters: Based on rock physics and random forward simulation,I test on the main domestic and foreign inversion technique including Prestack simultaneous inversion and prestack AVO inversion.Develop and perfect the scalar poisson ratio reflectivity,and achieve a better description of lithology and hydrocarbon of the reservoir with semi quantitative.4.Reservoir prediction and comprehensive analysis: The interpretation of structure and fracture is carried out on the results of high resolution seismic data processing;Sedimentary facies types were determined by core data and analysis of seismic sedimentary facies;According to the seismic lateral resolution and vertical resolution of well logging,I use high resolution geological statistics and multi attribute fusion technology to solve the problem of thin layer prediction effectively and realize the fine description of reservoir.5.According to the development of offshore oil and gas fields,I created an integrated technology of processing,inversion and reservoir.6.The research results are applied to Xijiang24-3 oil field,Yacheng13-1 gas field.The effect is very significant good with accurate description of the reservoir providing an important and accurate seismic information support to the development of oil and gas fields and to the adjustment the deployment of wells.