Reservoir Description For Dujiatai Reservoir At Shu 4th Section Of Shuguang Oil Field

Shu 4^th section located at right wing of Shu guang fault block in the middle of west slope, which is in west sunken of Liao He basin. It's a monocline fault block incised by a series steps fault, it's a complex structure area. it can be divided into seven main blocks: the 8th,13th,22th,30th,4-6-17,4-7-14,4-5-4block.the bury depth of Du jia tai reservoir changed from 905 to 1650 meters, it can be divided into 3 reservoir groups,10 sand sets,30 subzone. Clastic rock compositional maturity is low, it has thin sandstone granularity (the average median is 0.099mm), and the content of mudstone is high. Heterogeneity that of stratification, inner and areal is strong. the distribution of oil and water is complexes, the distribution of du I reservoir groups is small, The distribution of du III reservoir groups is near shu8 and west of shu22, most of eastern region of shu 4-7-14 was full of water, the average effective thickness is 2.1 meter. This oilfield has been explored for 30 years since 1976, it has experienced raising, steady, and descending periods, and it is at high water content and high off-take rate phase. Although pattern modification has been adjusted for many times, the pattern of injection and off-taking well isn't very well, as the reason of sand exit and casing damage. Because of heterogeneity, the distribution of remaining oil and quantity of remaining recoverable oil is complex.At the case of this oilfield geology status, using seismic-stratigraphic depositional systems to establish pool description; using theory of reservoir geology to analyze and establish fine 3D geology model; using performance evaluation based on 3D geology model and sedimentary facies to establish the model of distribution of remaining oil.1. according to the sedimentary evolvement of du jia tai reservoir and response of logging, it can be identified 3 main index beds and 4 assistant index beds at Shu 4th section, with 427 wells contrasted.2. on the base of fine stratigraphic correlation, microscopic structure research using by structure software could be helpful to drilling well.3.sedimentary system of du jia tai reservoir groups at Shu 4th section is facies model of braided river, the main sedimentary facies is delta front. As the sorting of braided river is well, porosity of underwater braided stream is large while cementation isn't well. according to sedimentary facies and logging facies analysis, sedimentary formation of delta front has three clear progradation-recession periods, reservoir groups of du II has the most palpable delta progradation.4. on the base of multi-well Log Interpretation, 3D geology model is built by using Kriging Simulation.5. textural maturity of Shu 4th section is low, the main pore types are intergranular pore-space and dissolution pore,subaqueous branch channel has most permeable zone,research of heterogeneity indicates that heterogeneity of du jia tai is medium, the most permeable zone of subaqueous branch channel lays in middle part, channel bar deposit has homogeneous formation.6.the distribution of oil is controlled by structure and sedimentary, it is structural and sedimentary oil reservoir, the results of field appraisal indicate that most of du jia tai reservoir areâ…¡,â…¢,main pay wasâ…¡,66.7 percent of du II reservoir groups is of II,and it's the best reservoir groups.