两性离子聚合物钻井液体系PL的研制

DEVELOPMENT OF ZWITTERIONIC POLYMER DRILLING FLUID SYSTEM PL

普通的聚合物钻井液在现场应用过程中暴露出一些问题,如在强造浆泥页岩地层时,常表现出抑制性不够强,钻井液的粘度与切力上升快,造浆严重,需要大量排放钻井液,增强聚合物钻井液抑制性时会显著影响流变性与造壁性,钻井液的静结构力强与形成的滤饼质量差等一系列问题。由此导致了新型两性离子聚合物钻井液的产生,由于两性离子聚合物分子结构中含有在粘土表面产生强吸附力的阳离子、非离子基团,在钻井液中表现出较强的抑制性、较好的流变性,使降滤失性调节与抑制性削弱的矛盾得以解决。通过对钻井液体系中的增粘剂、降粘剂及抗盐性降滤失剂的优化,筛选出了增粘与降粘效果好、抗盐性能好的两性离子聚合物,研制了两性离子钻井液体系PL的最佳配方:4%土浆+0.2%FA-367+ 0.2%XY-27+ 1.5%JT888-2+1.5%FT-1,实验结果表明:研制的两性离子钻井液体系PL具有较好的流变性与抑制性,能够满足钻井作业的顺利进行。

There were a series of problems existing in drilling into the strong mud-making shaly formation by use of the conventional polymer drilling fluid there, such as being poor inhibition property, rapidly raising viscosity and shear force, seious mud-making, having meed to increase the discharge capaqcity of drilling fluid, evidently influencing the rheologicl and wall-building properies while streng thening the inhibition property of polymer drilling fluid, being strong gel strength and being poor mud cake quality, etc. For this reason, a novel zwitterionic polymer drilling fluid PL was developed by the authors. The zwitterionic polymer is of strong inhibition property and good rheological behavior in drilling fluid because there are cations and nonionic groups, which are strongly adsorbed on the clay surface, in the polymer molecular structure, thus resolving the contradiction between adjusting filtration property and weakening inhibition property. Through optimizing the viscosifying agents, viscosity-reducing, agents and anti-salt filtration-reducing agents in drilling fluid systems, the excellent zwitterionic polymer drilling fluid system PL was developed. Its optimal formulation is as follows: 4% soil+0.2% FA-367 + 0.2% XY-27 + 1.5% JT888-2 + 1.5% FT-1. The test result indicated that it could meet the needs of drilling operation, having good rheological behavior and inbihibtion property.