东溪气田优化钻井综合技术

COMPREHENSIVE OPTIMIZED DRILLING TECHNOLOGY AT DONGXI GAS FIELD

川东东溪构造是一老探区,该构造2002年以来完钻的东浅1、东浅2、东浅3井等均获工业性气流。近几年完钻的东浅1、东浅2、东浅3井的机械钻速均为2.0～2.5m/h。经过综合分析,及时优化了东浅4井钻井设计,更改了井眼尺寸、井身结构及定向井工艺,优选钻井液体系,机械钻速提高到3.56m/h,且钻井成本也大大降低。为此,以可比性最强的东浅3井与东浅4井作对比分析,指出了先期完钻井的各项设计不足和带来的钻井后患,阐明了东浅4井优化钻井后取得的各项优化指标,特别是套管成本、机械钻速、定向井工艺技术的提高,推进了该区块的滚动勘探工作。

Many wells at the Dongxi structure, one of the old exploration zones in East Sichuan Basin, have already obtained industrial gas flow since being drilled and completed in 2002 like Dongqian-1, 2, 3, 4. However, the ROP of the wells Dongqian-1, 2, 3 are all at only about 2.0-2.5 m/h in recent years. Not only was the ROP of Well Dongqian-4 increased to 3.56 m/h but also the drilling cost was decreased sharply by optimizing its drilling design and drilling fluid, modifying bore size, well configuration and directional well technique after comprehensive analysis. So, comparing two wells with the strongest comparability, Well Dongqian-3 to Dongqian-4, this study pointed out disadvantages in previous design of drilled well and relevant drilling risks, illustrated each optimal index got in Well Dongqian-4 after optimizing drilling, especially the decrease of casing cost, the increase of drilling rate and the improvement of directional well technique, which would provide important references for exploration in this area.