渤海低渗油田定向井井身结构优化

Optimization of Casing Program for Directional Wells in Bohai Low Permeability Oilfield

渤海25油田沙河街组低渗储层地层压力系统复杂,一期开发时采用渤海常规井身结构,但是作业复杂情况频发,工期较长,导致成本高,整体经济效益较差。通过对地质油藏、地层特点做深入研究分析,优化出一套?355.6mm井眼×?273.1 mm套管+?241.3 mm井眼×?177.8 mm套管+?152.4 mm井眼×?114.3 mm尾管的井身结构及其配套提速技术。通过在2口井的应用试验,取得了较好的效果,2口井平均井深3607.5 m,平均钻井周期19.32天,钻井周期共计比基本设计节余5.37天,钻井时效比基本设计提高24%,同时小井眼钻井所使用的器材及材料费用相应减少,而且投产后产量较好,经济效益显著,具有广阔的应用前景。

The formation pressure system of Bohai 25 oilfield is complex. In the frst stage of development, the conventional casing program in Bohai was adopted, but the frequent complex situation and long construction period led to high cost with poor overall economic benefit. Through the study on slim hole technology in Thailand bay, combined with the actual situation in Bohai, a set of optimized easing program 355.6mm hole × 273. lmm easing ＋ 241.3ram hole × 177.8mm casing ＋ 152. 4ram hole × 114. 3ram liner and the support improved ROP technology was developed. Through the application tests in 2 wells, good results have been achieved with the average well depth 3607.5m and average drilling period 19. 32 days, drilling cycle saved 5.37 days and drilling efficiency increased by 24% in these 2 wells than the basic design. The costs of equipments and materials used in slim hole drilling go down accordingly and better yield and significant economic benefits are received in operation with broad application prospects.