Research On Mining Technology Optimization For Production Stabilization Of Liu Lin CBM

As the rapid development of economy in China and the condition of the shortage of oil and gas energy,Chinese requirement for the exploitation of CBM is growing.The coal seam in Liulin block is of low pressure,low permeability and low saturation,the gas well productivity is generally low,the basic study about CBM mining disciplinary is not perfect,and the foreign advanced mining technology in our country does not apply.The CBM mining uses extensive development pattern,it is based on the development concept of "drilling more well",and the emphasis of fundamental theory research in the field of mining efficiency of coalbed methane Wells of is not enough.In order to realize standardization and refinement of the CBM development,we must form a complete set of the CBM reservoir technology to achieve long-term stable yield.In this paper,based on the geological characteristics and production status of the CBM blocks,optimize the stable production technology pointedly,which is of great significance for the development of the CBM efficiently.According to the CBM well production performance,gas wells could be divided into not gas-injection-production well,low yield well,middle well and high yield wells,the mining stage can be divided into drainage period,and gas rising period,gas stable production stage and gas decreasing period.The influence factor index evaluation system in gas stable production stage has been established,the main index effected the yield of the CBM wells are gas content and permeability,followed by water content,the smallest influence factor is reservoir/aquifer thickness ratio.The first choice for coalbed methane development way of lifting is tubular pump for pumping unit.Combined with analysis of the coalbed methane well production performance,this paper optimizes the different development series of strata,different development stage of working fluid level decline,the mining working system optimization software is compiled on the basis of it,which can provide three available optimization data used in the field: bottom hole flowing pressure,displacement per day,working system).The achievements is with guidance and application value for the development of coal-bed gas field,which is of significance for the development of other similar coal bed.