新疆石油地质 ›› 2019, Vol. 40 ›› Issue (zk(English) ): 188-193.
CHEN Depo1, LIU Huancheng2, CHEN Shuning3
CHEN Depo1, LIU Huancheng2, CHEN Shuning3
摘要： The fifth member of Guantao formation is the main oil layer in the western District 7 of Gudong oilfield and the reservoir belongs to loose sandstones of meandering river deposition. At present, the remaining oil saturation of the target zone in newly-drilled wells is not consistent with the expected one during the oilfield development, so the original designed objects cann't be achieved. The effects of well adjustment and potential tapping in the existing wells don't match with the geological understanding, which increases the difficulties of oilfield stimulation and it is urgent to verify the relationship between the internal configuration elements of meandering-river point bar reservoirs and the remaining oil distribution. Based on the study of the cores obtained from sealed coring wells, the paper summarizes the amount of the lateral accretion layers and rock types within the point bar, analyzes the flowing characteristics of the lateral accretion layers with different lithologies and the remaining oil distribution within the point bar, unravels the key elements of the internal configuration of the point bar, obtains the thickness, occurrence and distribution of the lateral accretion layer, and then calculates the length and width of the point bar and the bankfull depth and width of the meandering river. Based on the data of logging, core and lab analysis, the internal configuration of the point bar in paired wells is analyzed and the high remaining oil saturation in the newly-drilled wells adjacent to water injection wells is reasonably explained. The study results show that the internal configuration of the point bar is the most important factor controlling remaining oil distribution and the remaining oil is mainly distributed in the reservoirs above the lateral accretion layers with relatively poor physical properties.
