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The Comprehensive Reservoir Evaluation Of The Upper ES4 Member In Dongfenggang Oil Field

Posted on:2010-01-18Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z Y ZhaoFull Text:PDF
GTID:1220360278960826Subject:Institute of Geochemistry
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By log data and interpretation, seismologic data analysis, core particular description, kinds of geochemical testing and analysis and so on, this paper comprehensively evaluates oil-gas reservoir of the upper ES4 member in Chexi depression, which includes eight parts, as stratigraphic correlation, structure elucidation, sedimentary microfacies analysis, diagenesis and dividing diagenetic stage, recovering paleotemperature and paleopressure, interpreting porosity and permeability by well log, reviewing reservoir characteristic and type, researching the relationship of lithology, physical property, electrical property and oilness, and look for the favorable place for prospecting and payable area. All of these, that are very useful for decreasing cost of exploitation, increasing efficiency of exploitation, maintaining oil-gas output.In the process of comparing strata, we choice seven type wells, sixteen well tie sections, and dividing three sands groups, eighteen layers and thirty night single sand bodies. According to difference of height on the surface of formation, fault displacement, fault growth index, we considered that the fault activity could control on the sedimentation, and after sedimentation of ES4 member, tectonic uplift is more stronger in the southern, and fault activity is main in the northern and eastern of Chexi depression. In work area, tensile stress is primary and chief, from late Mesozoic to Present, which had laevogyrated fifteen degrees.The primary type of sedimentary facies is delta, including some microfacies, such as distributary channel, underwater distributary channel, distributary mouth bar, distal bar and sand sheet and so on, all of which are favorable for reservoir to explore. In this area, paleocurrent direction is approximate from south to north, and longitudinal continuity of sand bodies is much better than lateral continuity. The main provenance is Wudi horseback, the secondary are Qingyun and Yihezhuang horsebacks.The clastic constituents of reservoir sands are composed of quartz, feldspar and debris, and clay minerals are made up of kaolinite, chlorite, illite and andreattite, and the pores are consisted of three types, as primary pores, secondary pores including moldic pores and intragranular pores, and fractures including disrupted and diagenetic shrinkage fractures, all of which are the smaller half length of pore-throat, the lower degree of sorting and connectivity. There are five kinds of diagenetic facies, which can be sequenced for oil content, as mixed cement facies, calcarinate facies, corrosion facies, compaction and fracture facies, clay cement facies. As deeper, the diagenesis is become to be stronger. From the lower to the deeper, diagenesis is divided into three phases, including middle diagenesis A1 phase, middle diagenesis A2 phase, middle diagenesis B phase.This area is always normal temperature system in all ages, where the north is surpressure and the south is normal pressure. The nonequilibrium compression had mainly brought on surpressure and the diagenesis is secondary to form surpressure. The high yield well can be result of the pressure coefficient from 1.1 to 1.3. The surpressure could restrain increasing strata temperature and diagenesis, fluid inclusions from forming.As the formation deeper, the porosity and permeability are become decreasing, but it has unconventional values in three abnormal zone, where the diagenesis and surpressure affect on the porosity and permeability. In work area, there are six reservoir types, consisting of oil layer, oil-dry interval layer, oil and water layer, oily water layer, water layer and dry layer. We interpret the effective thickness of oil layers is 531.2 meters, which includes five main layers, as 15layer, 25layer, 26layer, 33layer and 37layer.According to comprehensive evaluation, we consider that there are four blocks are the most useful for exploration activity than the others, which are seventy percents in total petroleum resources; there are four secondary blocks in eighteen percents of petroleum resources and six blocks in twelve percents of total resources.
Keywords/Search Tags:Stratigraphic Correlation, Structural Feature, Sedimentary Microfacies, Diagenesis, Temperature-pressure System, Reservoir Property, Reservoir Interpretation, Reservoir Evaluation
PDF Full Text Request
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