| In the development of coalbed methane, the well type should be matched withthe geology, reservoir, terrain, and different well types are suitable for differentgeological conditions. Based on the reservoir and structure characteristics, thereservoir complexity is analyzed under the structure control. Combined with theproductivity, the well types and patterns were put forward in the Zhuzang synclinal,Bide-Santang basin, Zhina coalfield, Guizhou province.The reservoir complexity is controlled by fault dip, falt slip, fault length, faultdensity and structure crvature. The Analytic hierarchy process method (AHP) is usedto quantitative analysis the reservoir complexity under the structure control. Thereservoir complexity simple areas and complex areas are the major in the study area.The shallow coal seams are controlled by the Zhuzang syncline and Digui anticiline,with the increase of the reservoirs’ buried depth, the control function of the folds areweakened gradually, while the large boundary faults control function has beenenhanced.In the reservoir complexity simple areas, the single well progressive can achievegood effect of production. The numerical simulation results show that the300×250mwell distance well pattern can achieve the best effect. In the reservoir complexitycomples areas, a new cluster wells model has been proposed. Compared with thesingle well progressive, the recovery of the new cluster wells has been increasedobviously. As the production continues, the recovery gap is reduced. With the newcluster wells method, the300×300m well distance well pattern can achieve the besteffect. With this well distance, the single well productivity of the gas system (1) and(2) is significantly higher than other well distances patterns. The productivities ofdifferent well distances in the gas system (3) are not clear. Compared with therecovery of the single well, it has been greatly improved with the new cluster wellsmodel. |
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