Reservoir Inversion And Target Prediction Of Gao81 3D Survey, North Of West Depression, Liaohe Basin

Gao 81 3D survey, a prospective area, lies in Northern of West Depression, Liaohe Basin. Dujiatai layer is a prime reservoir of this area, but its distribution is limited due to the evolution of structure and sedimentation. Our object is to know the distribution of oil pool and find next favorable area. Some new geophysical techniques are applied, such as coherence, 3D visualization, impedance inversion and neural network seismic multi-attribute inversion. Firstly, applying coherence, 3D visualization and time slices, author interprets structure detailed. The results show that most faults extend northeast and southeast, which make the structure of survey complicated. Gao71 east fault and Gao84 south fault, both construct new trap, are found, whose sealing properties are better. Secondly, the seismic and well log sequences are recognized and sedimentary systems, sedimentary facies including seismic facies are analyzed in detail according to cores, logs, seismic and other kinds data of the region, as well as 3D Visualization. The result shows that two sources exist: one is northeast and another is northwest that the favorable reservoir in Gao81 region is based on. Fan-delta, turbidite fan and lake are main types of sediments. Fan-delta develops well, and Fan-delta front is main reservoir whose distribution is between Gao81 and Gao80. Impedance Inversion shows that Gao81 east block is a prospective area. Neural network seismic multi-attribute inversion is a new technique, which deals with the problem of inversion without acoustic logs. Due to its high resolution and reliability, it can play an important role in predicting reservoir. It can predict any logs' curves such as resistivity log, so it could be used as detecting oil and gas. Finally we use the technique to find a favorable area rich in oil, and a trap, Gao81 east. When the thesis will be finished, good news comes that this trap has produced oil after drilling. It certifies that these techniques are adaptable to this field.In a word, author combines geological ways with advanced geophysical techniques to predict the distribution of reservoir and gets a satisfied result in practice.