This study focuses on the feasibility of reusing formation water as inhibitive base water for water-based drilling fluids (WBDFs) to reduce the need for freshwater and commercial salts. A real produced formation water (PFB) with known composition and a synthetic produced formation brine (SPFB) were compared to commercially available clay inhibitors, i.e., KCl and NaCl salts. Experiments show that the PFB and SPFB have acceptable free swelling indexes and sedimentation rates. According to the zeta potential measurements, they similarly decrease the charge of clay surfaces and reduce swelling of Na-bentonite. Besides, the cutting dispersion test illustrates that PFB and SPFB can reduce the interaction between the Pabdeh and Gurpi shales (Iranian formations) with drilling fluid. Drilling fluids made of the PFB and SPFB have rheological properties, including apparent viscosity, plastic viscosity, yield point, and gel strength less than a typical inhibitive WBDF made of NaCl. API filtration loss of both PFB- and SPFB-based drilling fluids at high bentonite concentrations (more than 12.5 wt.%) is similar to the same as the KCl-based drilling fluid, indicating their close inhibition power to the KCl solution. Finally, SEM analysis confirms that the texture/morphology of sodium bentonite exposed to the PFB and SPFB is close to that of the KCl solution and formation water inhibition power is more than NaCl and near to KCl. Eventually, formation water as a potential inhibitive water for water-based drilling fluids, is preferred to the commercial salts from both environmental and economic aspects.

这项研究的重点是将地层水用作水基钻井液（WBDF）的抑制性基础水以减少对淡水和商业盐的需求的可行性。将具有已知组成的实际生产的地层水（PFB）和合成生产的地层盐水（SPFB）与可商购的粘土抑制剂（即KCl和NaCl盐）进行了比较。实验表明，PFB和SPFB具有可接受的自由溶胀指数和沉降速率。根据ζ电位测量，它们类似地减少了粘土表面的电荷并减少了钠膨润土的溶胀。此外，切削分散测试表明，PFB和SPFB可以减少Pabdeh和Gurpi页岩（伊朗岩层）与钻井液之间的相互作用。由PFB和SPFB制成的钻井液具有流变特性，包括表观粘度，塑性粘度，屈服点和凝胶强度，均低于由NaCl制成的典型抑制性WBDF。在高膨润土浓度（大于12.5）下，基于PFB和SPFB的钻井液的API过滤损失 wt。％）与基于KCl的钻井液相似，表明它们对KCl溶液具有紧密的抑制能力。最后，SEM分析证实了暴露于PFB和SPFB的钠膨润土的质构/形貌与KCl溶液相近，地层水抑制能力大于NaCl且接近KCl。最终，从环境和经济方面考虑，地层水作为用于水基钻井液的潜在抑制水，比市售盐更可取。