渤海油田定向井井身结构优化及应用

井身结构优化是钻完井降本提效的主要措施之一。论证了目前渤海油田常规定向井所采用的?444.50 mm井眼(?339.73 mm表层套管)+?311.15 mm井眼(?244.47 mm生产套管)、?444.50 mm井眼(?339.73 mm表层套管)+?250.82 mm井眼(?177.80 mm生产套管)两种井身结构组合的优缺点，提出了?311.15 mm井眼(?273.05 mm表层套管)+?241.30 mm井眼(?193.67 mm生产套管)的井身结构，并论证了该组合的钻完井可行性。现场应用表明，与邻井相比，采用优化后的井身结构机械钻速可提高35.8%，单井可节约钻井成本约200万元，降本增效成果显著，具有非常广阔的应用前景。

Optimization of the casing program of directional well and its application in the Bohai Oilfield

The optimization of casing program is one of the important measures for the cost reduction and efficiency increase of well drilling and completion. The advantages and disadvantages of two casing programs which are currently used in the conventional directional wells of Bohai Oilfield were demonstrated, i.e., ?444.50 mm hole (?339.73 mm surface casing)+?311.15 mm hole (?244.47 mm production casing), and ?444.50 mm hole (?339.73 mm surface casing)+?250.82 mm hole (?177.80 mm production casing). Then, the casing program of ?311.15 mm hole (?273.05 mm surface casing)+?241.30 mm hole (?193.67 mm production casing) was put forward and its feasibility of drilling and completion was demonstrated. Field application indicates that compared with the neighboring wells, the rate of penetration (ROP) of the well with optimized casing program is increased by 35.8% and the single-well drilling cost is reduced by RMB 2×106 yuan, presenting remarkable achievement of cost reduction and efficiency increase. Therefore, its application prospect is promising.