Zhenjing Oilfield Shu Probe 2 Well Head Of Reservoir Description And Modeling

Zhenjing oil field is located on the south-west of Ordors Basin with oil-bearing area of5.73km2,the nature of lithology reservoir is low porosity, low permeability and lowcompression. Oil set C6 in the Upper Triassic Yanchang formation is one of the main oilproducing strata, but less study has been done in the block and many disputed question existabout sedimentary microfacies' characteristic and sedimentary environment of the oil set C6especially in recent years. With the developing of the farther studies in C6 reservoir ,it hasbeen a prominent obstacle to the next work for a long time. Focusing on these problems, thepaper follow a path from point(well) to line(cross section) ,to surface(map),to area(field), andadopts several advanced geologic theories and technologies, such as reservoir sedimentology,high-resolution sequence stratigraphy, facies-controlled stochastic modeling, to describe thereservoir characteristics and to build up the geological model of oil set C6, in ST2 block ,Zhenjing oil field . Through the research mentioned above, the following results are achieved:1,High-resolution sequence stratigraphy theory has been used to analysis Stackingpatterns of short-term cycle and divided oil set C6 into middle-term stratigraphic cycles:MSC1, MSC2 and MSC3. middle-term cycles are classified into 3 types of evolvementphases, i.e.slowly decreasing, transitorily rising, stably decreasing.2,240 meters core of 9 wells has been observed carefully and described delicately .it canbe divided 9 subfacies and 12 microfacies and it is considered that oil set C6 is composed ofbraided delta environment. the major type of sub-facies are deltaic front and predelta. Thesubaqueous distributary channel sand and distributary mouth bar are the major type of sand.3,Compining sedimentary parameters' distribution, sandbodies'plane distributing lawsare achieved. Because of the interaction of base level changes and Sediment supply,braideddelta of oil set C6 are classified into 4 types of evolvement phases, i.e.delta's initial period,delta's highly developed period, delta's intermittent period, delta's regenerative period.4,It was indicated that 9% and 0.5 md were the thresholds for porosity and permeabilityof prospective reservoirs, respectively. subaqueous distributary channel sand and distributarymouth bar were the main oil producing sandbodies, which had better physical properties, buthigher heterogeneity. The five reservoir evaluation parameters, including net-pay thickness,porosity, permeability and microfacies, were used in the composite quantitative evaluation ofthe reservoir by gray theory.5 ,Adopting multi-information cooperation, combining deterministic modeling andstochastic modeling, utilizing the sequential indicator and sequential Gauss simulation, the 3Dgeological model is built up. Scientific method of four steps restriction on thefacies-controlled modeling in braided delta front is brought forward, which means using theprobability, sequence of facies, and quantitative repository and variation function to constrainthe modeling process. The model reflects the distribution character of the subsurface geologysystem.