Songfangtun Oilfield F135 Wellblock Putaohua Reservoir Sedimentary Characteristics

Songfangtun Oilfield located in the northern Songliao basin, formed under the background of the bedrock protrusions in paleo central uplift zone of Sanzhao Depression, is an earlier developed oil field, part of the block has entered the high watercut period, the proportion of inefficient wells increase. The complex distribution of oil and water is mainly affected by the fault segmentation and rapid change of lithology, it is difficult for wells deploy. In order to have a better understanding of geological conditions, we need do fine reservoir sedimentary characteristics of Putaohua layer, make formulate feasible countermeasures, in order to improve the development effect of the oilfield.In order to guide the development and deployment of Putaohua Formation in F135 block of Songfangtun Oilfield, on the basis of previous studies on the Putaohua Formation, according to the well logging data, seismic data, core data and other dynamic data we study the sedimentary characteristics, plane distribution and vertical evolution of the study area. Establish high resolution fine stratigraphic framework and 1 facies, 2 subfacies and 7 microfacies model of Putaohua Formation in study area, draw 13 layers of sedimentary microfacies of Putaohua Formation, summarize the sedimentary facies planar distribution feature, the region’s sand body plane distribution and vertical phase play features. Study area is river control deltaic depositional system, mainly affected by the northwest provenance, sand body mainly develop in northwest-southeast, mainly distribute in the banded or intermittent banded, the sand body is mainly underwater shunt channel microfacies and some seats-like sand microfacies, vertical top-down mainly develop lake back type front, lake back transitional facies, lake into type front, lake back in front, lake in the transitional phase and lake into outer front. Finally predict the favorable facies belt, provide 4 suggestion wells.