%0 Dataset
%T Research papers on Key Technologies of drilling technology and wellbore working fluid (2016-2021)
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/5446c4cf-8eb0-4403-b6b2-38a42cb9759a
%W NCDC
%R 10.12072/ncdc.SRIPE.db1711.2022
%A Gao deli
%K Frozen soil layer;low temperature cementing slurry;low temperature drilling fluid;extended reach well
%X Papers on drilling technology and key technologies of wellbore working fluid. The publication time interval is 2016 / 7-2021 / 5, and the location is Beijing. With the increasing use of oil-based drilling fluid, it is necessary to study the mechanism of gas diffusion invasion and establish the quantitative calculation model of gas diffusion invasion. The gas diffusion and invasion channel is divided into five parts: gas and filtrate interface, filtrate retention area, inner filter cake area, outer filter cake area, inner wall of outer filter cake area and drilling fluid interface. Based on the analysis of gas diffusion and invasion mechanism, the control equation and analytical solution of gas diffusion and invasion in wellbore are derived. Based on the analytical solution, the quantitative calculation formulas of gas diffusion and invasion parameters (gas invasion rate under cyclic condition, total amount of gas in wellbore under cyclic condition, maximum concentration of gas under static condition and total amount of gas in wellbore under static condition) are given. Combined with the example analysis, the influence rules of reservoir length, reservoir porosity and drilling fluid filtration on gas diffusion and invasion are obtained. In addition to the maximum gas concentration at rest, the gas diffusion and invasion parameters have a linear relationship with the reservoir length.