The Fine Resevior Description And Geology Modeling Of Chang6Resevior Group Of Chai44Well Area In Xiasiwan Oil Field

The study area is Xiasiwan Oil Field Chai44area, which is located in the south of theYishaan Slope, in Ordos Basin. The main oil-bearing reservoir contains the Triassic YanchangFormation Chang3, Chang4+5and Chang6reservoir. The main study object is aroundChang61, Chang62, Chang63, of Chang6oil reservoir group. Carried on the fine reservoirdescription study. integrated multi-disciplinary knowledge, including the basin structure, theevolution of the deposition system, stratigraphic division correlation, sedimentarymicro-facies, petrologic characteristics, diagenesis, reservoir physical property, reservoirheterogeneity. Building the reservoir model, and predict the distribution law of reservoirporosity, permeability, oil saturation.According to the study of tectonic evolution history of the evolution of depositionalsystems, Carried stratigraphic division, the Chang6oil reservoir group is divided into Chang61, Chang62-1, Chang62-2, Chang63. Chang6oil reservoir’s sedimentary face characterbelongs to the dominated delta front face, including underwater distributary channel, lateralborder of subaqueous distributary channel and bay mud between distributary channels, Thethree micro-facies overlays each other in vertical. The underwater distributary channel has thebest reservoir properties. Sedimentary Micro-facies and sand body distribution agreement.The Chang6main oil-bearing layer developed in the deposition of underwater distributary channel sand body. The Chang6is mainly composed of the fine-grained feldspathicsandstone. Local development of microscopic cracks; porosity average of8.35%, median8.6%; average permeability is0.47×10-3μm2, median0.21×10-3μm2reservoir heterogeneity;reservoir sensitivity performance of middle-acid sensitive, medium-weak water-sensitive,weak salt sensitivity, weak speed-sensitive, weak alkali sensitivity; The Chang6reservoir forthe special low porosity and low permeability reservoirs, mainlyⅡb andⅢa class ofreservoir. Created the Random three-dimensional geological model of the long6reservoir,with the Petrel software. Established the petro physical model with the Sequential Gaussiansimulation method and Assign value methods, objectively reflect the distributioncharacteristics of the physical parameters of the reservoir sand bodies. Providing a referencefor the rolling exploration and development of the area.