Cementing Technique Research And Application Of The Coal Bed Gas In Fuxin Mining Site

The main components of the coal bed gas is methane, the coal bed gas is a kind of clean, efficient and safe new energy which is more than conventional petroleum, is a rich reserves of unconventional natural gas resources and has a very important exploitation value. The exploration and development of coal-bed gas in our country began late. The coal reservoir is shallow buried, micro-pores, porosity and pore pressure gradient is low, poor mechanical stability, easy to collapse and easy to pollution compared with the general hydrocarbon reservoir. This will bring great difficulties to the drilling and well completion of coal bed gas. Currently the coal bed methane well completion way are mainly open hole completion and casing perforated completion. In china, due to the limited of coal'property, 98% of coal bed methane well needs large hydraulic fracturing, negative pressure drainage mining. Therefore the application of open hole completion is little, casing perforated completion is the main well completion. Cementing technique is the key technology of the casing perforated completion. And slurry system is largely determines the cementing quality.According to the coal mine is shallow wells ,low temperature , the time of using the oil well cement cementing solidification is long, poor flow ability and on-site operation is inconvenience ,etc. For such problems, this paper studied and developed the fast solidification early strength oil well cement. This study according to the optimized particle size distribution principle, selection of different diameter of superfine cement, G class cement and other active imperceptible particle cementations materials, and combining the particle size distribution of the lightening admixture material to establish the reasonable closely accumulation model, develop a stabilizer, gel strength accelerant and other additives, as well as develop a new low density early strength slurry system. This slurry system has good theology, low water loss and no free fluid, right angle thickening, the slurry bond strength developing fast and has the excellent low-temperature early strength performance and achieve the on-site application requirements.