关键词: 钻井理论, 定向钻井, 井身剖面, 井眼轨迹, 数学模型, 设计方法, 优化设计

Abstract:

Currently,directional and horizontal wells are generally planned to be 2D arc-shaped well profiles.Conventional methods are generally poor in universality as they have to use respective formulas for different types of well profiles and only provide one set of possible solutions, which often requires many times of trial calculations to yield reasonable planned results.To solve the problems on the versatility of well profiles and design methods, the author gives a universal well profile and the constraint equations, and presents a new technique of planning a well profile in which any two characteristic parameters can be arbitarily selected as unknowns. The revelation of evolution regularity of well profiles makes the presented technique applicable to all kinds of well profiles with any combination of arc and straight sections.This result broke through the limitation of conventional methods for planning well profiles,provided a universal solution,achieved mutual validation and optimization among characteristic parameters,and solved some problems of the versatility and optimal design in planning a well profile.This new technique was also characterized by simple formulas,flexible and practical approaches,easy computer programming,etc.And it could be widely used in planning well tracks for directional and horizontal wells.The examples validated the scientificity and applicability of the method provided.

Key words: drilling theory, directional drilling, well profile, well trajectory, mathematical model, planning method, optimization design