Technical scheme for preparing slurry for crushed soft formation for downhole drilling

Abstract

The invention discloses a technical scheme for preparing slurry for crushed soft formation for downhole drilling. Firstly, a field rock core is analyzed in a laboratory, and the experiment of simulating actual formation conditions in the laboratory is completed; and secondly, practical drilling is carried out according to a field use method through slurry prepared in the laboratory so that experiment effects can be proved, and slurry meeting the drilling requirements under the geological conditions both in theory and under experiment conditions is obtained. By the adoption of the technical scheme for preparing slurry for crushed soft formation for downhole drilling, slurry required by drilling stress concentration area and soft rock strata easy to collapse is obtained, walls of drill holes are stable, the purpose of discharging powder out of deep holes is realized, the drilling efficiency and the drilling engineering quality can be effectively improved, and waste of financial resources, material resources and manpower for coal mine is reduced.

Description

technical field [0001] The invention relates to the technical field of coal mine hydrogeological exploration. Background technique [0002] At present, drilling in soft rock formations has always been one of the difficult problems of drilling technology at home and abroad. Underground drilling in coal mines is especially carried out in complex strata such as (Permian Upper Shihezi Formation, Lower Shihezi Formation and Shanxi Formation). The biggest obstacle in deep vertical hole drilling is the discharge of rock dust and hole collapse. The deeper the hole is drilled, the more strata are drilled, the longer the construction period, the more complex the hole will be, and the greater the construction difficulty will be. The factors are the complex geological structure, the concentration of in-situ stress, the soft stratum which is easy to swell when exposed to water, and the capability of drilling equipment is insufficient. The internal reason is that in the soft rock drillin...

AI Technical Summary

Problems solved by technology

[0006] Considering the requirements of drilling flushing fluid for drilling under the condition of concentrated in-situ stress in soft rock, the adaptability of existing flushing fluid to soft rock was analyzed, and polyacrylamide (PAM) with good flocculation, adhesion, and drag reduction The PAM aqueous solution is used as the flushing fluid for drilling deep vertical holes in soft rock formations in stress-concentrated areas, scientifically proportioned and used reasonably, which solves the problems of hole wall stability, lubrication and deep hole powder drainage. Effectively improve the drilling efficiency and the quality of the drilling project. In order to ensure the control of drilling on site, the test and data analysis are first carried out indoors.

Images