高温深井微裂缝封堵评价方法及其应用——以松辽盆地徐深气田为例  

A new evaluation method for micro-fracture plugging in high-temperature deep wells and its application:A case study of the Xushen Gas Field in the Songliao Basin

作　　者：刘永贵[1,2] 宋涛 徐用军[1] 

机构地区：[1]哈尔滨工业大学 [2]中国石油大庆钻探工程公司钻井工程技术研究院

出　　处：《天然气工业》2016年第2期78-83,共6页Natural Gas Industry

基　　金：中国石油天然气集团公司科学研究与技术开发项目"特殊工艺井钻完井配套技术研究与应用"(编号:2013T-0308-001)

摘　　要：松辽盆地徐家围子断陷深层白垩系营城组火山岩地层微裂缝发育,钻进过程中经常发生井壁剥落、坍塌和恶性漏失等井下复杂,而采用常规钻井液封堵评价方法在模拟裂缝形态和效果评价方面与现场实际存在着较大的差距。为此,提出了有针对性的高温深井微裂缝封堵评价方法 ：使用与岩石成分接近的硅铝酸盐材料制作了一种新型微裂缝岩心模型,微裂缝开度介于1~50μm,重复性好,缝面粗糙度、孔隙发育情况及缝面形态与天然裂缝更加接近,弥补了传统方法的不足;自主设计了微裂缝封堵评价装置,工作温度达200℃,工作压力介于3.5~5.0 MPa,可模拟井下工作液的流动状态,具有钻井液用量少、操作简便及成本低等优点。XSP-3井现场试验结果表明,采用上述评价方法优选的钻井液配方有效地解决了微裂缝发育的火山岩地层难以安全钻进的难题,改善了钻井液的粒度分布,提高了钻井液封堵防塌能力,保证了该区深层裂缝性地层的安全钻进。Micro-fractures are developed in volcanic layers of Cretaceous Yingcheng Fm in the deep part of Xujiaweizi fault depression, Songliao Basin. In the process of well drilling, various complex problems happen, such as borehole wall slabbing and collapse and serious fluid leakage. Based on conventional drilling fluid plugging evaluation methods, the real situations cannot be presented accurately, especially in fracture feature simulation and plugging effect evaluation. Therefore, a specific micro-fracture plugging evaluation method was put forward especially for high-temperature deep wells in this paper. It is a new type of micro-fracture core model with the fracture apertures in the range of 1-50 ktm. It is made of aluminosilicate that is compositionally close to natural rocks. It is good in repeatability with fracture-surface roughness, pore development and fracture-surface morphology close to natural fractures. Obviously, this new model has no deficiencies of the conventional methods. A new micro-fracture plugging evaluation instrument was independently designed with operating temperature of 200~C and operating pressure of 3.5-5.0 MPa. It can be used to simulate the flow regime of downhole operating fluids, with the advantages of low drilling fluid consumption, convenient operation and low cost. The plugging capacity of the organo- silicone drilling fluid system was evaluated by using this instrument. It is shown that the grain size distribution of the drilling fluid is improved and its anti-collapse capacity is enhanced. Based on the field test in Well XSP-3, the safe drilling problems in volcanic layers with developed micro-fractures are effectively solved by using the drilling fluid formula which is optimized by means of this evaluation method. And the safe drilling is guaranteed in the deep fractured formations in this area.

关 键 词：高温高压 微裂缝 封堵实验 评价方法 钻井液 火山岩 松辽盆地 徐深气田 

分 类 号：TE28[石油与天然气工程—油气井工程]