| Ganguyi oilfield located intersection of baota district and yanchang in Shaanxi province, whose tectonic position is the south east of shanbei slope, a secondary structure unit of the Ordos Basin. Regional geological activity is weak, the leader of the yanchang formation reservoir group is the most important oil-bearing series. The chang6 reservoir in general characterized by low mineral maturity and high textural maturity, and the formation of the reservoir has low porosity, low permeability, low oil saturation characteristics. Predecessors to research of sedimentary facies and reservoir characteristics is more in Ganguyi oilfield, but go to ditch the scientific research work is relatively weak, the low degree of geological research. Therefore, the research on sedimentary and reservoir characteristics can provide basis data for the calculation of reserves and making development plan.In this paper, based on regional stratigraphic correlation, combined with drilling, well logging data to extend the leader of the 6 reservoir group of small layer fine classification, for the structure characteristics of the top surface analysis, the distribution of sedimentary facies and reservoir analysis provides accurate stratigraphic research unit. Research shows that chang6 reservoir of each small layer top surface structure form the overall performance for west slope, tectonic angle is less than 1 °, average grade 3 to 4 mlkm, and in Tang231 ~ Tang 176 well block of the development in the Midwest of form a complete north east, south west toward the anticline structure, each small layer between the structure of the form has strong inheritance.The sedimentary microfacies study shows that chang6 reservoir sedimentary system type IS a set of water back under the background of constructive delta front deposition and microfacies types mainly underwater distributary channel and distributary bay. Underwater distributary channel, the favorable reservoir space for oil and gas enrichment, distributary bay between mudstone and silty mudstone can be used as lateral occlusions, also can be used as a cover, directly for the research of district chang6 reservoir oil and gas enrichment provides good shelter and preservation conditions. Chang6 reservoir sandstone rock type for feldspar sandstone, clastic particles psephicity successively round angular ~ time is given priority to, the separation degree is in ~ good, relatively poor physical condition, belong to low to very low porosity, low to ultra-low permeability reservoir, but the small layers between the reservoir physical property were similar, generally controlled by sedimentation and sand body distribution, porosity and permeability distribution range is relatively uniform, under the condition of certain fracturing, can improve the physical conditions, can still get good output.Combination of Ganguyi oilfield reservoir classification standard, comprehensive evaluation and planning of gully district 6 reservoir types is Ⅱ, Ⅲ reservoir, have a certain reservoir conditions, belongs to the effective reservoir, reservoir evaluation level is good ~ medium.The Yanchang group mature hydrocarbon source rock, the chang6 reservoir group delta front composite channel sand body, superimposed shall sand layer and microcracks forming favorable channel, the lithologic trap formation period and favorable hydrocarbon expulsion period of organic configuration factors such as joint action, make Ganguyi oilfield planning ditch area has favorable hydrocarbon accumulation conditions, reservoir types are lithologic reservoir, reservoir types for lithologic reservoir, oil and water mix storage, no obvious edge and bottom water, its distribution is mainly controlled by the physical properties of the underwater distributary channel sand body. Reservoir drive type as the elastic displacement,overall for west east shallow deep reservoir buried depth. |
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