燃爆诱导及酸处理新技术在川西须家河气藏的应用

APPLICATION OF PROPAGATED BLAST AND ACID TREATMENT TECHNOLOGY IN CHUANXI XUJIAHE GAS RESERVOIR

川高561井须二储层是川西地区深层须家河组异常高破裂压力储层的典型代表,在加重酸酸化时井底压力达到159.6MPa时,储层仍然未能压开,异常高破裂压力严重制约了该类储层的勘探开发。针对该井须二段4911～4943m、4959～4995m储层的地质特征及工程条件,采用燃爆诱导压裂技术和酸处理技术的有机结合,现场完成75kg药量的燃爆和83m3酸的酸压联作处理,在地面泵压89～93MPa下施工排量达到0.955～1.02m3/min。该层射孔试破没有获得天然气产能,通过燃爆诱导压裂和酸处理联作后,井底停泵压力降低了26.73MPa,有效的改善了油气渗流通道,在油压42MPa,套压43MPa下天然气输气量达到8.2885×104m3/d。该复合新技术在川高561井须二异常高破裂压力储层的成功实施,为川西深层须家河储层解决异常高破裂压力问题提供了新的技术思路。

Chuangao 561 well,the second reservoir interval of Xujiahe,is the typifier of deep Xujiahe abnormal high fracture pressure reservoir in the Chuanxi area. When it was acidized,the bottom hole pressure was high up to 159.6MPa,but the container rock didn't split. The exploratory development of this kind of reservoir was severely restricted because of the abnormal high fracture pressure. According to the geologic characteristics and engineering condition of the second reservoir interval of Xujiahe,which includes these intervals:4911-4943m and 4959-4995m,the propagated blast and acid treatment technology were used in Chuangao 561 well. During the acid fracturing,75kg ammunition had been detonated and 83m3 acidizing fluid had been pumped. When the surface pump pressure was 89-93MPa,the delivery capacity rose to 0.955-1.02m3/min. After perforating and fracturing test,the gas flow rate of the two intervals was little. Through adopted propagated blast and acid treatment technology,at the moment of termination of pumping,the bottom hole pressure reduced 26.73MPa. The path of filtration of gas had been improved efficiently. When the oil pressure was 42MPa and the casing pressure was 43MPa,the gas flow rate reached 8.2885×104m3/d. The successful application of propagated blast and acid treatment technology in Chuangao561supplied a new technique approach for solving abnormal high fracture pressure reservoir in the Chuanxi area.