大宁—吉县地区煤层气水平井固井技术研究与应用  

Cementing Technology of Horizontal Coalbed Methane Wells in Daning—Jixian Area

作　　者：齐奉忠 于永金 刘子帅 

机构地区：[1]中国石油集团钻井工程技术研究院,北京102206

出　　处：《非常规油气》2015年第1期54-60,共7页Unconventional Oil & Gas

基　　金：国家科技重大专项项目36"煤层气钻井工程技术与装备研制(二期)"(2011ZX05036-006);国家科技重大专项课题"煤层气井完井技术及设备"(2011ZX05037-001)部分研究成果

摘　　要：大宁—吉县地区煤层气资源丰富,但该地区煤层裂缝和割理发育,煤质软、机械强度低,井壁稳定性差,地层承压能力低,为保证水平井固井套管安全下入,保证煤层段固井质量及施工安全,开展了水平井固井配套技术研究。采用紧密堆积和颗粒级配技术,优选了增强材料DRB-1S及适合的减轻剂,根据该地区煤层气井固井特点,提出了水泥浆性能要求,优选了适合低温固井的降失水剂DRF-300S及与之配套的早强剂,开发了失水量小于50m L、低温下早期发展快的低密度和常规密度水泥浆配方;从提高钻井液润滑性、通井、扶正器选择及安放等方面提出了保证长水平煤层段套管安全下入的措施;通过在"V"形井造穴处注入沉砂,防止了"U"形管效应的出现。水平井固井的成功应用表明,措施选择合理,优选的水泥浆配方可以有效保证对软煤层段的良好胶结。形成的配套技术为该地区及类似地区煤层气水平井固井提供了借鉴作用,可推广应用。Daning--Jixian Area, a place enriched with coal-bed methane （CBM） resources, is characterized by developed fractures and cleats, soft coal, low mechanical strength, poor borehole wall stability and low bearing capacity of the strata. Studies have been conducted on supporting technologies for cementing horizontal wells to guarantee safe running of casings into horizontal wells and to ensure cementing quality and safe operation performed at the coal bed interval. The reinforcing material DRB-1S and appropriate lighter have been preferably selected by employing dense packing and particle size distri- bution technology. Requirements on the performance of cement slurry have been put forward according to cementing charac- teristics of CBM wells in this area. The fluid loss control agent DRF-300S, which is suitable for cementing at low tempera- tures, and its auxiliary early strength agent have been optimally selected. The formula of low- and conventional-density ce- ment slurries with fluid loss less than 50mL and rapid development of early strength at low temperatures has been devel- oped. Measures to ensure safe running of casings into long horizontal coal bed intervals have been proposed from perspec- tives of improving the lubricating property of drilling fluid, well drifting and the centralizer selection ＆ installation. Occur- rence of U-tube effects is prevented by injecting sand at the V-shape well cavitation point. The successful application of cementing in two horizontal wells demonstrates that the measures have been selected reasonably and the optimally selected cement slurry formula can effectively ensure good bonding of soft coal bed intervals. The developed supporting technologies serve as guidance for the cementing of horizontal CBM wells in this area and other similar areas and can be put into exten- sive application.

关 键 词：煤层气 水平井 固井 居中 水泥浆 套管 

分 类 号：TE256[石油与天然气工程—油气井工程]