成本约束条件下的套管柱优化设计

传统的等安全系数法套管柱设计基本思路是“套管受到的载荷×安全系数小于或等于套管的强度”,其核心是强度安全原则,而较少考虑套管的成本。在现代钻井工程中,套管柱费用所占比例很高,所以研究既考虑强度又考虑成本的套管柱设计方法尤为重要。以传统套管柱设计力学模型为基础,结合线形规划理论,建立了成本约束条件下的套管柱设计的数学模型,并建立了图解法求解的步骤。实例验证表明,该设计方法具有求解简单、所设计的套管柱成本最低的特点。

OPTIMIZING CASING STRING DESIGN UNDER COST CONSTRAINT

The basic concept of traditional casing string design with the equal safety coefficient method is "load of string × safety coefficient ≤ casing strength", the core of which is the principle of strength safety, with little consideration of casing string cost. In modern drilling engineering, casing cost takes a very large share of the drilling cost, thus study of casing string design method that considers both the strength and cost principles is very important. Based on the traditional mechanical model of casing string design and in combination with linear programming theory, a mathematical model of cost constrained casing string design is built and the procedures are presented for solving the mathematical model with graphic method. Case study shows that this design method is easy to solve and the designed casing string has the lowest cost.