膨胀水泥浆体系在苏丹1/2/4区块水平井固井中的应用

随着苏丹1／2／4区块的深入开发，为了加快开发主力油层，提高原油产量，降低钻井成本，GNPOC在此区块布置水平井开发任务。所开发的区域主要分布于Heglig，Munga，Simbir，Bamboo区块，油层所在是Zaqar和Bentiue地层。此层位具有高渗透，地层温度高，易塌、气窜等复杂问题，尤其是Heglig和Munga地区井壁坍塌严重。为此，根据地质资料、井身结构和对水平井注水泥的技术要求，科学合理设计施工工艺，优选出适合此地区固井施工的冲洗液和隔离液，特别是经过努力实践，开发出了新型膨胀水泥浆体系，此体系具有高强度、低失水、无析水、防气窜之功效。结合使用哈里伯顿CPT—Y4大功率固井车，精确计量和自动密度控制，该体系水泥浆目前已在7口水平井施工中得以应用，均为优质井。现正在被大量使用，此体系的开发，解决了该固井技术难题，创造了中国固井在海外首次水平井作业一次成功的历史记录，具有较高的经济和社会效益。

APPLICATION OF EXPANDING CEMENT SLURRY SYSTEM IN HORIZONTAL WELL CEMENTING IN 1/2/4 BLOCK OF SUDAN

With the development of 1/2/4 block in Sudan, in order to improve crude oil output and reduce drilling cost, horizontal wells mainly were distributed over Heglig, Munga, Simbir, Bamboo area by GNPOC, reservoirs are situated in Zaqar and Bentiue formation. The horizon has some features, such as high permeability, high temperature, easy caving and gas channeling, etc. The hole collapse is very serious in Heglig and Munga area. So, based on geologic data, casing program and technical requirement of cementing in horizontal well, the washing fluid and spacer fluid suited for these areas were optimized, and a new type expanding cement slurry system was developed. The characters of the system are: high strength, low filter loss, non-bleeding and anti-gas channeling. The cement slurry system has been successfully used in seven horizontal wells. It solved the difficulty of cementing technology, has higher social and economic benefit.