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Reservoir Comprehensive Evaluation And Productive Advantageous Regions Prediction On Chang6Reservoir In Jiyuan Area

Posted on:2015-02-04Degree:MasterType:Thesis
Country:ChinaCandidate:S LiFull Text:PDF
GTID:2250330428471536Subject:Mineralogy, petrology, ore deposits
Abstract/Summary:PDF Full Text Request
In recent years, the achievement of exploration work in Jiyuan area is outstanding. Its newly incremental proved reserves of2013, with more than one hundred million tons of reserves, ranked the first in our country. The geological condition of Jiyuan oilfield is very complex, many negative factors, such as poor reservoir property, property plane changing quickly, intense diagenesis, various types of pore throat, fluid space frame features variable as well as strong heterogeneity affect its production. All above factors result in lower single well productive capacity, large production difference between adjacent well and unsatisfactory exploitation effect. For purpose of solving above problems, this article regards the reservoir comprehensive evaluation as the research content. By virtue of multiple experimental testing method and various data analysis, we conduct a comprehensive analysis of reservoir lithology, pore throat structure, percolation characteristic and reservoir heterogeneity from small layers division, classification of microfacies and research of the sandbodies distribution. Next, select reasonable main parameters to conduct comprehensive reservoir evaluation, and then using the test data to predict the single well production capacity, finally divide the favorable reservoir zones by comprehensive analysis of reservoir evaluation results and productivity prediction results. The results are as follows:(1) The tectonic and sedimentary environment in the study area is stable, and the development of the underwater distributary channel and underwater interdistributary bay microfacies of lacustrine delta front is control by the provenance from northwest and northeast. From Chang63to Chang61, the scale and size of the sand body on the plane is expanding step by step as well as the thickness on the vertical is thickening.(2) The Chang6reservoir in this area belongs to the typical low porosity and low permeability reservoir, the reservoir property becomes better from Chang63to Chang61.Reservoir characteristics are as follows:frequent migration and multi-period overlaid of depositional sandbodies, property changing quickly on the plane, developing intercalation between layers, containing many small thickness single sand body, beddings develop within the layer, vertical permeability anisotropy is strong, the spatial configuration of pore throat is complex, reservoir heterogeneity is strong. (3) The reservoir is mainly composed of fine-grained and very fine arkose, which are characterized by medium composition maturity and textural maturity. The quantity of interstitial material shows an increasing trend from Chang63to Chang61. The diagenesis is strong, and the compaction and cementation greatly destroy the pore, but local metasomatism and large areas of dissolution improve reservoir property. The main types of pore are dissolved pore and intergranular pore, throat types are mainly plates and curved sheet throat, pore and throat combination types are mainly fine pore throat and micro pore throat.(4) The Chang6reservoir in the study area can be divided into four categories. The first class reservoir is mainly the fine sandstone which is characterized by thick single sand, good properties and oil potential, large pore space, relatively coarse throats, good reserve capacity and permeability, but minimal in distribution range compared with other types. The second and third class reservoir are composed of very fine-grained sandstone, with overall good reservoir property, moderate-strong heterogeneity and wide distribution. The fourth class reservoir is the worst reservoir in the study area, which is poor in properties and oil potential and moderate-strong in heterogeneity.(5) The single well production capacity in the study area were affected by many factors, grey correlation analysis showed that porosity, permeability, effective thickness, oil saturation, acoustic transit time as well as electrical resistance have greater degree of influence on productive capacity. According to well productivity prediction results and the reservoir comprehensive evaluation results, I kind favorable area were select about62.37square kilometers, Ⅱ kind favorable area were sum to449.69square kilometers.
Keywords/Search Tags:Jiyuan area, Chang6, Reservoir characteristics, Reservoir comprehensiveevaluation, Favorable area prediction
PDF Full Text Request
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