The Research On Comprehensive Evaluation And Reservoir Of The Third And Fourth Section Of The Gaotaizi Oil Layers In Qijia Area

After more than fifty years of exploration in Daqing oil field development, the conventional reserves decline year by year, dense oil reservoir has become the direction of exploration and research focus on the current. Its area high counter reservoir is located in Qijia-gulong depression in Songliao Basin, cretaceous Qingshankou formation of lower cretaceous has good hydrocarbon source rock condition, sedimentary characteristics of delta front and front delta facies, tectonic characteristics for the dome anticline structure. The tight reservoir of the study area have good oil and gas generation and preservation conditions.Tight reservoir usually has a complex geological environment, the author by aligning the third and fourth section of the Gaotaizi oil layers macroscopic characteristics,(sedimentary characteristics, lithologic characteristics), the microscopic characteristics of the reservoir,(physical characteristics and pore types structure) aspects of research, combined with field measured data of the study area reservoir classification and evaluation, and favorable area prediction. Through which the research area density provides some references for the real reservoir exploration and development.Described by core observation, logging data and other related information, and determine the terms in the third and fourth section of the Gaotaizi oil layers two types of sedimentary characteristics of delta front and front delta subfacies, subject to underwater distributary channel deposits. Research in the reservoir rock types are mainly lithic arkose and feldspathic lithic sandstone and clay mineral with illite, chlorite and give priority to the palm.Reservoir porosity is 13.3% on average, among them, the porosity is lower than 10% of the proportion accounted for 32.1% of overall; Air permeability reservoir with an average of26.76×10-3μm2, of which, the proportion of less than 0.1×10-3μm2 accounted for 31.7% of overall. Effective reservoir porosity lower limit is 2.69%, permeability lower limit of0.03×10-3μm2, belongs to low permeability tight reservoir type, low porosity, permeability and poor physical property as a whole. Diagenetic stage into rock stage A- B section, secondary pore dissolution for reservoir main reservoir space. Verified, the reservoir physical properties in the study area was mainly affected by sedimentary facies and diagenesis. Comprehensive the above conditions, according to the sedimentary characteristics, core features, physical properties, pore types, structure will put the third and fourth section of the Gaotaizi oil layers are divided into four types of reservoirs, and predict seven favorable areas.