Study On Macroscopic Heterogeneity Of Oil Reservoirs In North Oil Reservoir Of Nasuke Oilfield In Gasquole Oilfield

Gasikule oilfield N1～N21reservoir is located in the Qaidam Basin, and it is one of the main reservoir of Qinghai Oilfield. Because of the complex geological conditions, moisture content is increasing during harvesting and injection is unknown, largely because its storage layer macroscopic heterogeneity is unclear, so figuring out the macroscopic heterogeneity of the reservoir is important to improve oil recovery.Through collecting its regional geology, core data, logging data and production performance data, combing the results of thin layer division and contrast in Gasikule oilfield N1～N21VI oil group analyzing and identifying its deposition facies by core facies and log facies of the oil group. And this sets the stage for the macroscopic heterogeneity of VI oil group and made the following findings:①The study area was divided into three types of microfacies, underwater distributary channel, mouth bar, distributary bay.②The thin layers of VI oil group contains five kinds of rhythmic patterns:positive rhythm pattern, reverse rhythm pattern, homogeneous rhythm pattern, composite positive rhythm pattern, composite reverse rhythm③There are two types sandwich in VI group, sandwich and calcareous shale oil mezzanine④By calculating the coefficient of variation, onrush coefficient and differential coefficient, the heterogeneity of inner layers is strong.⑤By calculating the parameters of drilling layers, the heterogeneity of in-layer is weak-moderate.⑥By analyzing the plane distribution of porosity and permeability to study the plane heterogeneity, concluding that porosity, permeability is controlled by sedimentary facies and they varies between different facies but the difference is relatively small in the same facies.