钻头选型中的地层分层技术

Study on dividing strata in drill bit selection

郝亚龙 葛云华 崔猛 纪国栋 殷鸽 黄家根 2

中国石油集团工程技术研究院有限公司，北京 102206 中国石油勘探开发研究院，北京 100083 中国石油集团渤海钻探工程有限公司，天津 300457

CNPC Engineering Technology R&D Company Limited, Beijing 102206, China Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China CNPC Bohai Drilling Engineering Company Limited, Tianjin 300457, China

在钻头选型过程中，仅按可钻性对地层进行分层的传统方法易导致钻头与地层适应性差，影响钻头破岩效率。为解决这一问题，首先以岩石力学实验为基础，建立岩石抗钻特性参数预测模型；其次将Fisher算法、投影寻踪理论及实码加速遗传算法相结合，设计了一种适用于多维抗钻特性参数地层分层的新方法。其原理是先利用投影寻踪原理和遗传算法将多维抗钻特性参数数据投影到一维直线上，得到一条表征综合抗钻特性的剖面曲线，再用Fisher算法对得到的综合抗钻特性剖面曲线进行有序聚类，从而实现地层的合理划分。通过在窿18井下沟组地层分层中的实际应用表明，该方法分层效果良好，基本符合地质实际，能够为钻头选型中的地层分层提供数学理论依据。

In the process of bit selection, the traditional method of stratifying the formation according to the drillability is easy to cause poor adaptability of drill bit and formation, affecting the rock breaking efficiency of drill bit. To solve this problem, firstly, based on rock mechanics experiments, a parameter prediction model for rock anti-drilling characteristics is established. Secondly, combining Fisher algorithm, projection pursuit theory and real-code accelerated genetic algorithm, a new method for multi-layer anti-drilling characteristic parameter stratigraphic division is designed. Its principle is to use the projection pursuit principle and genetic algorithm to project the multi-dimensional anti-drilling characteristic parameter data onto a one-dimensional line to obtain a profile curve that characterizes the comprehensive anti-drilling characteristics. Finally, using the Fisher algorithm, the obtained comprehensive anti-drilling characteristic profile curves are sorted in order, so as to achieve reasonable stratification of the stratum. The practical application in the stratigraphic stratification of the Cretaceous Xiagou Formation in the Well Long 18 of the Qingxi Block, Yumen Oilfield, shows that the method has good stratification effect and basically conforms to the geological reality. This method can provide a mathematical theoretical basis for stratigraphic stratification in bit selection.

10.6056/dkyqt202002022