Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containi...Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containing-exploitation. Oil exploitation from vertical wells is becoming more and more inefficient. The reservoir type, with water displacing oil and the remaining oil distribution are specifically studied in order to improve the efficiency of the recovery ratio. An integrated scheme for adjusting horizontal wells has been designed and the key technique of the scheme optimized. The study shows that: 1) the positive rhythm of fluvial depositional features is the internal cause of the flooding of oil reservoirs while water injection, injection-production patterns and accumulative petroleum production are the external causes; 2) oil-water driving patterns have transferred from edge water advancing to bottom-water-coning; distribution of the remaining oil mainly concentrates in the upper rhythm and top of the middle rhythm in Ng33 members; 3) a great deal of remaining oil is enriched in high positions of faults, in axes of tiny structures, in stagnation areas among water-injection wells and oil-wells and in tectonic saddle areas with sparse wells. Compared with vertical wells, horizontal wells have advantages such as high recovery, high off-take potential, high critical output, large controlling areas and long time of bottom-water breakthrough.展开更多
An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented. Consideration of the elastic and pla...An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented. Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress. Based on this, a confined pressure unloading test was conducted by the use of the ＂gas-containing coal tbermo-fluid-solid coupling 3-axis servo seep- age＂ experimental apparatus. Thus, gas flow patterns in the elastic and plastic zones were derived from an experimental point of view. Darcy＇s law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields. The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment patterns.展开更多
基金Projects 2003CB214603 supported by the National Basic Research Program of ChinaDMSM200803 by the Open Fund of Key Laboratory of Deposi-tional Mineralization & Sedimentary Mineral, Shandong Province
文摘Oil reservoirs with secondary bottom water in Ng33 members (in Guantao formation, Paleogene system) of Lin2-6 fault block in Huimin depression (Bohai Bay Basin) have entered the late stage of ultra-high water-containing-exploitation. Oil exploitation from vertical wells is becoming more and more inefficient. The reservoir type, with water displacing oil and the remaining oil distribution are specifically studied in order to improve the efficiency of the recovery ratio. An integrated scheme for adjusting horizontal wells has been designed and the key technique of the scheme optimized. The study shows that: 1) the positive rhythm of fluvial depositional features is the internal cause of the flooding of oil reservoirs while water injection, injection-production patterns and accumulative petroleum production are the external causes; 2) oil-water driving patterns have transferred from edge water advancing to bottom-water-coning; distribution of the remaining oil mainly concentrates in the upper rhythm and top of the middle rhythm in Ng33 members; 3) a great deal of remaining oil is enriched in high positions of faults, in axes of tiny structures, in stagnation areas among water-injection wells and oil-wells and in tectonic saddle areas with sparse wells. Compared with vertical wells, horizontal wells have advantages such as high recovery, high off-take potential, high critical output, large controlling areas and long time of bottom-water breakthrough.
基金supported by the National Basic Research Program of China (No.2011CB201203)the Fundamental Research Funds for the Central Universities (No.CDJZR10240019)
文摘An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented. Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress. Based on this, a confined pressure unloading test was conducted by the use of the ＂gas-containing coal tbermo-fluid-solid coupling 3-axis servo seep- age＂ experimental apparatus. Thus, gas flow patterns in the elastic and plastic zones were derived from an experimental point of view. Darcy＇s law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields. The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment patterns.
