Characterization Of Fans On The North Side Of The Western Steep Slope Zone Of Damintun Depression And Effective Reservoir Prediction

Damintun Depression is one of the three major depressions in Liaohe Depression,located in the northeast of Liaohe Depression.The sandy conglomerate bodies deposited in the Paleogene Sha 4 Member in the northern part of the west steep slope belt have a wide distribution range,a large thickness,and good oil and gas accumulation conditions.The exploration potential is huge,and there has been a lack of targeted deployment research techniques.The geological characteristics of the conglomerate bodies in this area make it difficult to understand the structural characteristics of complex structural belts in the study;multi-stage sand bodies are superposed,single-well cycle division,and sedimentary facies belt determination are difficult;conventional post-stack wave impedance inversion cannot be effective Prediction of oil-bearing sand bodies.To this end,this paper collects seismic data of 380km2in the western steep slope zone of Damintun Sag.On this basis,the ancient geomorphology of the target interval in the study area during the deposition period and the period of massive oil and gas migration was restored;the stage division of thick wells and conglomerates in 42 wells was completed;the sequence sequence stratigraphy of 54 wells in the study area was performed The division and sedimentary facies analysis show that the vertical evolution of the fourth member of the Shahezi Formation of the Anfutun-Santaizi fan body in the Damintun depression is obtained;eight skeleton sections are selected for the analysis of the depositional system pattern on the continuous well section,and applied simultaneously Seismic methods are used to characterize the evolution characteristics of the sedimentary subfacies in the vertical direction and the distribution characteristics in the horizontal direction.And other data,carry out"four-sex relationship"research,establish and improve the effective reservoir identification standard of the sandy conglomerate body,and carry out the effective reservoir division of the whole area to determine the favorable facies belt;Structure,using a variety of technical methods to carry out effective reservoir prediction of sandy conglomerate bodies.Through the research of this paper,it is believed that the resistivity curve can better identify the deep sandy conglomerate formation cycle than the natural gamma curve.According to the characteristics of the formation cycle,the lower part of the fourth member of the Shahejie Formation is subdivided into three sand layer groups.The inversion can clearly distinguish the lithology changes in each section on the inversion profile,which improves the accuracy of the fan characterization.The study found that the reservoir's oil-gas bearing has a good correlation with the natural potential,and established an effective reservoir According to the standard,the favorable area of the fourth reservoir on the effective sand:27.5km~2.Favorable area under the 4th sand:37.2km~2.Provide sufficient theoretical basis for the next step of exploration and deployment.