基于构造裂隙填图技术的煤储层裂隙发育特征预测与验证

Forecast and validation of coal reservoir fractures based on structural fracture mapping technology

利用构造裂隙填图技术,在新疆阜康白杨河矿区地表围岩中实测了388个观测点,根据观测点构造裂隙的发育特征划分破碎等级,预测了地下煤储层构造裂隙的优势方向和发育特征,并利用6口煤层气井的产量数据、压裂曲线和井径扩大率进行验证。结果表明:地表围岩中观测点破碎等级较高的区块,煤储层内构造裂隙系统发育,天然裂隙联通情况良好,渗透率较高,煤层气井产量较高,压裂曲线的形态以先高后低型和波浪型为主,井径扩大率一般大于15%以上;观测点破碎等级低的区块,煤储层内构造裂隙系统发育不足或严重不足,天然裂隙联通情况较差,渗透率较低,煤层气产量为中产或低产,压裂曲线的形态为上升型,井径扩大率一般小于7%。利用该方法预测煤储层构造裂隙发育特征与工程数据吻合度较高,证明了该方法的有效性和可靠性,为有类似地质条件的煤层气开发区块煤储层裂隙系统预测,提供了一种新思路和新技术。

Using structural fractures mapping technology,388 observation points were measured in the sur- rounding areas in Fukang Baiyanghe Mining area, Xinjiang. According to the observation point structural fractures development determine the level of broken and forecast the structural fractures of the under- ground coal reservoir advantage direction and development characteristics. It was verified by using 6 pro- duction data of coalbed methane wells,fracturing curve and hole enlargement rate.The results show that： the surface observation point in the surrounding rock broken rank high block, the coal reservoir structural fissure system development, natural fissure communication in good condition, high permeability, higher coalbed methane well production~ fracturing curve shape is low after high first type and wave type, the hole enlargement ratio is generally greater than 15%.The surface observation points in the surrounding rock broke rank low block,the coal reservoir structural fissure system has no development,and natural fissure communication is in bad condition with low permeability,and low coalbed methane well production; fractu- ring curve shape is rising type,and the hole enlargement ratio is generally less than 7~.The result of pre- dicting coal reservoir structure fracture characteristics by using this method and engineering data alignment is higher.For combed methane development zone with similar geological conditions of coal reservoir,predic- tion fissure system provides a new way of thinking and new technology.