Study Of Seismic Reservoir Prediction Of The Changxin Formation In The Fuling Area

There were many seismic pot-stack inversion methods with different characteristics and applied ranges. A single method was commonly applied to predict reservoirs, so it was hard to get a good result. Here a novel inversion workflow, which was different with traditional strategy, was proposed and discussed. Three post-stack inversion methods including recursive inversion, constrained sparse spike inversion and neural network inversion were jointed to in-crease the resolution, reliability of the result, and gain much information on reservoir rocks and fluid parameters during reservoir forecasting. The technique is adopted to integrate seismic, geological and well-log data to get the P impedance data cube and other geophysical property data cube. The result shows that the new approach is feasible, effective and useful. It provides high precision data for reservoir prediction.In the exploration of reservoirs, the applications of seismic attributes make it possible to use seismic information completely. The analysis of seismic attribute is predicting lithology and lithofacies, reservoir physical and oil-bearing properties based on seismic attributes through extracting subtle information from seismic data, simultaneously combing geological and drilling data. The flow of analysis is as following:making sure the relationship of depth-time and accomplish horizon calibration; making extraction and optimization of seismic attributes and analysis. The analysis of seismic attributes mainly analyses reservoir qualitatively and identifies deposition boundary.Fuling area lies east of Sichuan basin. It is east of the Da chigan gas fields, west of Datianchi gas fields. According to paleomagnetic data, the Sichuan Basin was located in the low latitudes near the equator in the Changxing Period when the climate was warm and humid. The climate characteristic was one of the reasons for reef widely developed in the Permian. In the east of KaiJiang-LiangPing trough, many gas fields of reef flat were found, such as Puguang gas pool, huanglongchang gas pool, Gaofengchang gas pool etc. Meanwhile, in the west of KaiJiang-LiangPing trough, many gas fields of reef flat also were found, such as yuanba gas pool, longgang gas pool etc. Fuling area was west of KaiJiang-LiangPing trough in the Changxing Period. In the2010, WellXinglong1set of tests obtaining gas production51.7×104m3in the Changxing formation. To see the exploration prospects and comprehend reef flat development and distribution characteristics. On the guide of a multi-disciplinary theory, this thesis, with geology association with geophysics as the main line, according to drilling data, log data, seismic data and combining with the regional geological background, carry out to the single well analysis and well comparison which instruct seismic faces analysis and sedimentary distribution of the plane characterization. We analyze geophysical response characteristics of the reservoir using log data analysis with forward modeling technique. Also, union with seismic inversion and extraction of seismic attributes which are sensitive to reservoir development in the area, we carry out reservoir prediction. In the end, we run comprehensive evaluation of reservoir and determination favorable exploration targets area.By combing with geology and seismic, we analyze geophysical response characteristics of the reservoir in the study area and propose for reservoir prediction method, it is that bonding with seismic facies, we firstly confirm the favorable development zone of reef flat by sensitive seismic attributes, and then carry out impedance inversion and gamma inversion, and pick up the reservoir of reef flat on the impedance inversion section from which we remove mudstone, predict reservoir thickness of the23rd-order sequence on the plane in the end. With taking into account the sensitive attributes and local small structures, Integrated seismic facies, sedimentary facies, impedance inversion and reservoir thickness prediction, we comprehensively evaluate and predict favorable zones of the study area. In the first circle round, we think there are4favorable zones, including two type Ⅰ, two type Ⅱ and one type Ⅲ. In the second circle round, we think there are5favorable zones, including two type Ⅰ, two type Ⅱ and two type Ⅲ.