Abstract:

As the main weighting agent of oil?based drilling fluids, barite has many problems with high?density oil?based drilling fluids. In order to explore the applicability of micro?manganese mineral powder in oil?based drilling fluids. The particle size distribution and microscopic morphology of barite and micro?manganese ore powder were analyzed by laser particle size analyzer and scanning electron microscope. The differences in rheology, water loss and wall?building, lubricity, settlement stability, and reservoir protection performance between barytic petroleum?based drilling fluid system and micromanganese slag oil?based drilling fluid system were studied. The results show that under the condition of low density, the difference between the micromanganese ore powder system and the barite system is small; under high density conditions, the micro?manganese ore powder system has low viscosity and high cutting, the viscosity coefficient of the mud cake is less than 0.10, the sedimentation density difference is less than 0.03 g/cm³, and the permeability recovery rate after acid dissolution is higher than 95.00%. Its rheology, lubricity, sedimentation stability, and reservoir protection performance are better than the barite system, but compared with the barite system, the micro?manganese ore powder system has a large water loss and poor mud cake quality. It is recommended to compound the micro?manganese ore powder with a weight Spar to improve the water loss of the system. The research results fully reveal the difference in performance between the micro?manganese mineral powder oil?based drilling fluid system and the heavy crystal oil?based drilling fluid system, and provide support for the micro?manganese mineral powder to improve the performance of high?density oil?based drilling fluids, and also increase the weight of high?density oil?based drilling fluids. It also provides a new development direction for the application of ultra?high density oil?based drilling fluid weighting agents.

Key words: Micromanganese ore powder, Barite, Rheology, Reservoir protection

摘要：

重晶石是油基钻井液的主要加重剂，但是其加重的高密度油基钻井液存在诸多问题。为了探究微锰矿粉在油基钻井液中的适用性，采用激光粒度分析仪和扫描电镜分析了重晶石和微锰矿粉的粒度分布和微观形态，对比分析了重晶石油基钻井液体系和微锰矿粉油基钻井液体系在流变性、失水造壁性、润滑性、沉降稳定性、储层保护性能方面的差异。结果表明，在低密度条件下，微锰矿粉体系和重晶石体系差异小；在高密度或超高密度条件下，微锰矿粉体系低黏高切，泥饼黏滞系数小于0.10，沉降密度差小于0.03 g/cm³，酸溶后渗透率恢复率大于95.00%，其流变性、润滑性、沉降稳定性、储层保护性能均优于重晶石体系；微锰矿粉体系比重晶石体系失水量大，泥饼质量差，建议将微锰矿粉中复配重晶石以提高体系的失水造壁性。研究结果全面揭示了微锰矿粉油基钻井液体系和重晶石油基钻井液体系性能的差异，对微锰矿粉改善高密度、超高密度油基钻井液的性能提供支撑，也为超高密度油基钻井液加重剂应用提供了新的发展方向。

关键词: 微锰矿粉, 重晶石, 流变性, 储层保护性