Log Evaluation Method Research In Water Flooded Zone In Heavy Oil Block Qi40

Block Qi40 is located in south part of west ramp region of west depressed area in Liaohe Faulted Basin. It is a complex trapped heavy oil reservoir controlled by faults, formation, and lithology. Its explored reserve is 3721×104t, and its intended zones are of Lianhua oil layer in lower part of the third segment of Shahejie group. Cyclic steam injection and steam drive development from 1987 have changed pore structure, physical property, fluid type, and pressure of the formation. Static response characteristics and dynamic development effect to heavy oil reservoir show that conventional log evaluation method cannot meet the development of Block Qi40. Steam drive development style throughout the whole block from 2006 needs more detailed information about porosity, permeability, and residual oil saturation to optimize development program of steam driving well groups. These are the background of the research.Based on analysis to geologic information, log data, test data, and oil recovery performance, the research built up adaptable shale content, porosity, and permeability log interpretation models according to core analysis data and laboratory data by mathematic statistics method to improve computation accuracy of reservoir parameters of the block. Reservoir oil saturation calculated by reservoir parameters and preproduction data is used to study saturation variation throughout the steam huff and puff stage. Water flooded layers are identified and evaluated through integrated analysis to wireline log data, mud logg data, and production performance, including induced polarization potential log data and test data. Multiple-well integrated evaluations are developed from logging data computation and study in single well to sum up reservoir parameters variation in the block and to establish log interpretational criteria. It can provide reliable basis to upcoming fully implementation of steam driving development in Block Qi40.