In order to plan the optimal development model for different coal reservoirs, combined with production data and static geological data, the numerical simulation technology was applied to analyze the main controlling factors of single well productivity, and to divide geological unit of Zhengzhuang block and optimize the development model.The result shows that the difference of productivity of vertical well is mainly caused by the mismatch of hydraulic fracturing technique with geological characteristics of regional coal reservoir. The single well productivity is controlled by coal body structure, desorption pressure and ground stress. Zhengzhuang block was divided into four types of development geological unit. According to the numerical simulation, the reservoirs in type Ⅰ and Ⅱ development geological units are suitable for vertical well hydraulic fracture, and the reservoirs in the type Ⅲ and Ⅳ development geological units are suitable for multi-branched horizontal well. The optimized well spacing is 280 m in the type Ⅰdevelopment geological unit, the single well productivity can reach 2 000 m3/d or above, and the yield rate is 10.8%.The optimized well spacing is 240 m in the type Ⅱ development geological unit, the single well productivity can reach 800-2 000 m3/d, and the yield rate is 10.2%. The optimized well spacing is 80 m in the type Ⅲ development geological unit, the single well productivity is 3 000 m3/d, and the yield rate is 7.2%. The optimized well spacing is 60 m in the type Ⅳ development geological unit, the single well productivity is 3 200 m3/d, and the yield rate is only 3.1%, so it is risk to put into production under current economic technology.
YANG Yuchuan
,
LI Fengjie
,
DAI Tingyong
,
LI Junwu
,
YANG Chengjin
. Geological unit division and development model optimization of coalbed methane: a case study from Zhengzhuang block in Qinshui Basin[J]. Lithologic Reservoirs, 2016
, 28(6)
: 125
-133
.
DOI: 10.3969/j.issn.1673-8926.2016.06.017