Study On The Characteristics Of High-temperature Pulping Of Commonly Used Clays And The High-temperature Drilling Fluid System Of Reclaimed Soil

Research on the development and utilization of geothermal resources is a major frontier research topic in contemporary earth science and energy industry.It is of great significance for solving the increasingly serious energy shortage and global environmental problems.China is rich in geothermal resources.The national "Thirteenth Five-Year Plan" specially prepared the geothermal industry development plan.The development prospect of the geothermal industry is very broad.Currently,how to efficiently develop and utilize geothermal resources is one of the key issues facing the geothermal industry.During the exploration and exploitation of geothermal resources,the performance of the high-temperature drilling fluid system has become a key factor affecting geothermal drilling costs,drilling schedules,and drilling construction safety.In the process of geothermal drilling,the drilling fluid slurry performance under high temperature environment is the key to suspending the cuttings and forming high-quality mud cake,which is directly related to the smooth progress of drilling.In view of the urgent practical problems of the current geothermal drilling high-temperature drilling fluid system,such as complex formulation,inconvenient preparation,wide range of additives,low-temperature performance instability,and high cost,etc.,starting from the study of common high-temperature pulping characteristics of clay,the preparation of high-temperature pulping performance is preferred It is of great scientific significance and practical engineering value to modify the slurry mineral and adjust its performance by optimizing the high-temperature treatment agent,and then develop a new high-temperature drilling fluid system suitable for geothermal drilling.The method of combining theoretical analysis,experimental research and micro-analysis was adopted to systematically carry out the research on the characteristics of high-temperature slurrying of commonly used clay and the high-temperature drilling fluid system of reclaimed soil.Common pulping clay minerals such as sodium-based bentonite,montmorillonite,sepiolite,palygorskite and rectorite are preferred,and their structural characteristics are characterized by XRD analysis and infrared spectroscopy analysis.?,200 ?,220 ?,240 ?)pulping performance,rheological performance and salt resistance performance of the system.Retort soil with good high-temperature performance is preferred,and acidification modification,high-temperature calcination,inorganic modification,sodium modification and organic modification methods are used to conduct comparative test research on the modification effect of the rectorite and determine the organic modification As a modification method of rectorite.On this basis,a high-temperature treatment agent is preferred to further adjust the high-temperature performance of the modified rectorite,and then to develop a high-temperature drilling fluid system suitable for geothermal drilling,and systematically evaluate its high-temperature comprehensive performance.Thus,a set of high-temperature drilling fluid technology method system suitable for geothermal drilling is established.The main research results are reflected in the following aspects:(1)Through comparative test analysis on the microstructure and high temperature stability of common pulping clay,it is found that the high temperature stability of the rectorite is better.Moreover,it still has excellent pulping rate and rheological properties under high temperature environment of 220 ?,so it is preferred as the pulping clay mineral of high temperature drilling fluid.It has laid a good foundation for the modification of high-temperature pulping clay minerals and the research of high-temperature resistant drilling fluid system.(2)The effect of acidification modification,high-temperature calcination,inorganic modification,sodium modification and organic modification on the preferred pulping clay-Rector soil was compared and tested.The results show that organic modification Modification effect is better.And in organic modification,special colloid(LP)has better modification effect on rectorite.The modified high-temperature pulping rate and rheological properties of the reclaimed soil have been significantly improved.(3)On the basis of the reclaimed soil after modification,suitable high-temperature fluid loss additives and plugging anti-collapse agents are preferred to meet the high-temperature drilling performance requirements of geothermal wells.Finally,a new high-temperature drilling fluid system based on modified rectorite suitable for geothermal drilling was developed,and its comprehensive properties such as temperature resistance,collapse resistance,lubricity and salt resistance were evaluated.The research results provide a theoretical basis and scientific basis for the expansion of high-temperature drilling fluid slurry clay minerals and modification treatment research,and provide a new solution from the high-temperature drilling fluid system for solving the key problems of high-temperature geothermal well drilling.At the same time,the research results also have reference value and reference value for the research of other high temperature resistant drilling fluid systems similar to drilling engineering.