微锰加重剂减轻钻井液对油气层损害研究的新进展

重晶石在储层段钻井液中使用时，会对储层带来损害，且后续作业很难恢复，而微锰（Micromax）作为高密度钻井液的新型可酸溶加重材料，目前已开始应用于储层段钻井液中。综述了微锰加重剂对储层保护钻井液性能的影响，并分析了微锰提高钻井液储层保护特性的机理。其均一、高硬度、高球度的颗粒特征，可以保证微锰侵入储层后具有良好的返排特性，可降低对储层的伤害。微锰还具有可酸化的特性，调研了适用于微锰酸化的酸液，并对比了酸化前后对储层渗透率的变化，通过优选合适类型、浓度的酸液，在酸化后可消除钻井液对储层的损害。 

New Progresses Made in the Study of Minimizing Damage to Oil and Gas Reservoirs with Micronized Manganese Ore Weighting Agent

Barite used in drill-in fluids causes damage to the reservoir formations and the permeability impaired by the damage is quite difficult to recover. Micromax, a new acid soluble micronized manganese ore weighting agent, has recently been used in drill-in fluids. This paper summarizes the effects of Micromax weighted drilling fluids on the protection of reservoirs and analyzes the mechanisms with which the Micromax is used to improve the performance of drilling fluids in protecting hydrocarbon reservoirs. Micromax after invading into the reservoir formations can be flowed back because of its particle properties such as uniformity, high hardness and high sphericity, which are helpful to the mitigation of formation damage. Micromax is acid soluble. Acids suitable for the acidification of Micromax are investigated and the effects of Micromax before and after acidification on the physical properties of the reservoirs are compared. Reservoir damage can be eliminated by acidification with a suitable acid fluid of proper concentration.