Delay Angle Wire-line Core Drilling Hole Wall Stability Analysis And Research On Drilling Fluid

Depending on the cooperation project work of the study of gentle angle wire-line core drilling which was undertaken by Central South University and Jinchuan Group, this paper, according to special performance requirements of gentle angle wire-line core drilling, and consulting experience and laboratory and field tests at home and abroad, this paper manufactures suitable drilling fluid system to prepare for implementation of the drilling.The gentle angle wire-line core drilling is researched in three aspects: At the First, this paper summarizes and analyzes influencing factors of hole wall stability and measures for stabilizing hole wall. At the second, aiming at its suitable materials selection and performances, this paper analyzes suitable drilling fluid system. At the end, through indoor tests, this paper analyzes application of the drilling fluid in different formations and improves it.In this research, unstable formations, which are drilled in, are first divided in the mechanical stability and the watersoaking stability. From ground stress, mechanical properties of rock, the hydrodynamic pressure, drilling oblique angle, drilling azimuth angle and so on, we summarize analyze influencing factors of hole wall stability and summarize the suitable materials selection and performances of the drilling fluid.According to special performance requirements of gentle angle wire-line core drilling, and consulting experience and laboratory and field tests, we research on characteristics of different materials and manufacture suitable drilling fluid system.The field practice shows that:the drilling fluid manufactured has the carrying capability, ensure the success of the gentle angle wire-line core drilling, and is of certain guiding and practical significance.