Research And Application Of Formate Drilling Fluid

Drilling fluid, the blood of well drilling, is the decisive factor to a successful well drilling of high quality. Now with the increasingly complex reservoir structure, difficult drilling technology and more attention payed on environment, it puts forward higher request to drilling fluid. Formate drilling fluid without solid-phase which is a kind of water-based drilling fluid, non-toxic, meets the environmental protection requirements, but also has good temperature resistant properties and hydraulic characteristics, nice rejection capability and the ability to fight pollutions, especially has favorable compatibility with the reservoir, all this make it has a good effect of reservoir protection. In this paper, we firstly conducted a detailed study of the mechanism of formate; Then we optimized TJ-1 as filtration educing additive, JYW-3 as treating agent for protecting oil layer, TXZ-2 as adhesion promoter, and finally we got the formula of the drilling fluid system. Through lots of experiments, we evaluate the drilling fluid's performance in all aspects, including the weighting up performance, the temperature resistant property, the hydraulic characteristic, the ability to fight pollution, the rejection capability, the oiliness and the compatibility. At last we used the drilling fluid to the wells in Huan 633 block in Liaohe Oilfield to evaluate the application effect: the drilling fluid can steady the sidewall and suspend the cuttings, it is completely presented regular bore hole and satisfied to the drilling requirements, formation testing shows the output of the well using it is higher than the other wells. Thus, we can draw the conclusion: formate drilling fluid system has great potential of development and application value.