Fine Reservoir Description Of Block Wen51 In Pucheng Oilfield

This article takes reservoir of block wen51 in Pucheng oilfield as an example, uses highresolution sequence stratigraphy theory, bases on sedimentation response of base level,analyzes deposit volume distribution and its associated differentiation, correlates isochronolstrata and builds up fine stratum framework of reservoir. In the cycling framework of baselevel, correlation relationship has been set up between reservoir inhomogeneity andhydrocarbon distribution and gas and base level cycle. Hydrocarbon production property andresidual oil distribution have also been studied in the framework. According to these contents,the article has carried out the following aspects of study.1.Based on core study, combining with structural background and sedimentation, afterhydropower analyzing, it comes clear that lower S2 of fault block51 in Pucheng oilfieldbelongs to lacustrine delta sedimentation system, which is big delta sedimentation developedin shallow lacustrine. As delta deposition prograding rapidly, various rapid progradationproperties have been developed: from depositional sequence, it is lacustrine invasion deltabecause sandstone mainly appears as normal grading and normal cycle without inversegrading of normal delta. Sedimentary micro facies study shows principle reserving sandbodyis channel sandbody and the secondary is front sandbody and far sandbody.2.High resolution sequence stratigraphy framework has been built after basal levelcycling analysis. 4 levels of basal level cycling have been identified in the cores respectivelynamed super short term cycle, short term cycle, middle term cycle and long term cycle. Thisstudying section includes 1 long term cycle, 8 middle term cycle and 50 short term cycle(super short term cycle is so small that it can only be identified on the cores).3.Physical interpretation model has been established with reservoir inhomogeneity,which directly provides the basis for reservoir development production. Lithology-electricityanalysis suggests that porosity has positive correlation with interval transit time but negativecorrelation with Gamma, while permeability has good index correlation with porosity,according to which interpretation model has been built and logging interpretation has beendone with standard logging data accurately reflecting the property of the well. By reservoirinhomogeneity study, micro inhomogeneity analysis has been made for inter layer, innerlayer and the plane, among which inter layer indicates strong inhomogeneity.4.Development response and hydrocarbon distribution study provides geological basisfor development adjustment. Crude hydrocarbon distribution is under the control of thelocation of basal level cycle. Sandbody with high reserve and high reserve abundancedominantly lies in the lower of basal level, while sandbody with low reserve and low reserveabundance always has correlation with high position of basal level.