G函数分析在威荣页岩气田压裂中的应用
Application of G function to fracturing in Weirong shale gas field
尹琅 1刘琦 1宋燕高1
作者信息
- 1. 中国石化西南油气分公司石油工程技术研究院,四川 德阳 618000
- 折叠
摘要
为了提高四川盆地南部威荣气田下志留统龙马溪组页岩储层压裂形成的人工裂缝复杂程度和压后产能,通过对前期15口水平井人工裂缝复杂程度定量评价、G函数的压裂影响因素研究以及提升裂缝复杂程度措施研究,确定了下一步合理的压裂参数和暂堵工艺.研究结果表明:①威荣气田压裂形成的人工裂缝多为二类复杂缝,G函数波动系数与天然气无阻流量具有较强的正相关性,复杂裂缝比例越大、复杂程度越高,压后效果越好;②提高压裂规模和排量,开展暂堵有助于提高人工裂缝的复杂程度;③合理的用液强度为28 m3/m左右,合理的加砂强度为2.4～2.6 m3/m,施工排量应提升至16 m3/min以上;④暂堵工艺应以缝口为主、以缝内为辅;⑤基于研究结果形成的主体压裂工艺现场应用18口水平井,裂缝复杂性得到较大程度提高,压后天然气无阻流量提升超20%,取得较好的增产效果.结论认为,G函数分析在页岩气压裂裂缝复杂程度的评价和工艺参数优化方面具有较好的适应性,对类似气田的开发具有一定的借鉴意义.
Abstract
In order to improve the complexity of hydraulic fractures and the post-frac productivity in shale reservoirs of Longmaxi Formation,Weirong gas field,southern Sichuan Basin,the complexity in the previous 15 horizontal wells was evaluated quantitatively and fracturing controls on G function were discussed to make measures against this complexity im-provement.Furthermore,parameters in the following fracturing and a temporary plugging process were determined.Results show that(i)the induced fractures in this field are mostly type Ⅱ complex ones.The fluctuation coefficient of G function is in strongly positive correlation with absolute open flow(AOF).The higher the proportion and complexity of complex frac-tures,the better the post-frac effect;(ii)enlarging fracturing scale and displacement and performing temporary plugging are conducive to the complexity improvement;(iii)the reasonable fracturing-fluid and sanding intensity is 28 m3/m and 2.4-2.6 m3/m,respectively,and the construction displacement shall be increased to over 16 m3/min;(iv)the plugging should be carried out dominantly at the fracture opening and secondarily in the fractures;and(v)the elemental fracturing process formed has been applied to 18 horizontal wells,whose stimulation effect is remarkable with a great increase in the com-plexity and the AOF increased by over 20%.In conclusion,G function is better applicable to evaluating the fracture com-plexity and optimizing technological parameters,and can be used for references on similar gas fields.
关键词
页岩气/压裂/G函数/人工裂缝/复杂程度Key words
Shale gas/Fracturing/G function/Hydraulically induced fracture/Complexity引用本文复制引用
基金项目
中国石油化工股份有限公司科技部项目(P22041)
出版年
2024
NETL
NSTL
万方数据