Development And Performance Evaluation Of Modified Humic Acid Fluid Loss Additive For Oil-based Drilling Fluids

With China's shale gas resources exploration and development,vigorously promote,especially the successful development of Fuling shale gas coke dam,oil base drilling fluid system of shale inhibition,can effectively prevent the collapse of the widely used.The oil base drilling fluid filtrate reducer is an important part of drilling fluid,which is an important part of the drilling fluid,which is an important part in the control of fluid loss and stability of oil based drilling fluid.So the exploration of modified humic acid is suitable for oil based drilling fluid filtrate to evaluate the performance of the products is of great importance for domestic shale gas resources exploration and development,and promote the development of oil based drilling fluid loss agent synthesis.In this paper,the humic acid preparation of oil based drilling fluid with modified humic acid filtration reducing agent prepared by chloride amide two step process system.First through the chemical calculation using Gaussian software to verify the thermodynamic feasibility of acyl chloride amide two step preparation of modified humic acid filtrate reducer,the theoretical foundation for the next step of the test pad.In the preparation of modified humic acid,first by single factor test and orthogonal test to determine the optimal synthesis of modified humic acid reduction reaction parameters of filtration:acylation reaction temperature is 60 DEG C,acyl chlorination reaction time 2h,amidation reaction time 5h,humic acid and modifier ratio for 12:3.The oil base drilling fluid is prepared by modified humic acid filtrate reducer for performance evaluation,test results show that the modified humic acid filtration reducing agent amount was 3%when the room temperature control of high temperature and high pressure,pressure loss of water loss in 2.0ml,less than 8.0ml.The experimental results also show that it has a certain anti pollution and compatibility,compared with other commercially available oil based filter has a good performance in reducing the performance of the drilling fluid.Based on the modified humic acid oil solubility,particle size distribution analysis indicate that modified humic acid particles in the oil phase of oil soluble,average particle size reduced,the degree of dispersion increased;SEM cake by adding modified humic acid after oil based drilling fluid filter cake density to improve the porosity.Reduce;electrical stability test shows that the modified humic acid filtrate reducer has assisted emulsification,improve drilling fluid stability.In the above mechanism,the modified humic acid plays a good role in reducing filtration loss in oil based drilling fluid.