The problem of lost circulation is a direct consequence of the presence of fractures or high permeability. Lost circulation material (LCM) is used to treat the loss that occurs or proactively strengthen the wellbore of the potential loss zones. The polyacrylamide (PAM)/Polyethylenimine (PEI) cross-linkable polymer gel is proven to work best in zone-sealing and plugging applications. In addition to their thermal stability, the fact that these gels are flexible gives them the advantage of deforming and sealing-off multiple and complex near wellbore fractures.

The primary objective of this study is to investigate the gelation kinetics of the PAM/PEI cross-linkable polymer to be used in drilling fluids formulations to enhance wellbore stability and strength. Different combinations of polymers and crosslinkers were evaluated; potential polymers were screened for gelation kinetics and gel strength in typical drilling mud formulations. The gelation time of the polymer-based drilling mud formulation is determined in salt-free and in saline systems. The results on rheological properties and gelation kinetics were used to prepare a gelling mud formulation using PAM/PEI cross-linkable polymer as LCM. The produced gel was thermally stable under high-temperature-high-pressure reservoir conditions, which will result in enhanced wellbore strengthening.

漏失的问题是裂缝或高渗透率的直接结果。漏失循环材料（LCM）用于处理发生的损失或主动加强潜在损失区的井眼。事实证明，聚丙烯酰胺（PAM）/聚乙烯亚胺（PEI）可交联聚合物凝胶在区域密封和堵塞应用中效果最佳。除了它们的热稳定性外，这些凝胶具有柔韧性的事实使它们具有变形和封闭多个复杂井眼裂缝的优势。

这项研究的主要目的是研究用于钻井液配方的PAM / PEI可交联聚合物的胶凝动力学，以提高井眼的稳定性和强度。评估了聚合物和交联剂的不同组合；在典型的钻井泥浆配方中筛选了潜在的聚合物的凝胶动力学和凝胶强度。在无盐和盐水系统中确定基于聚合物的钻井泥浆配方的胶凝时间。流变性质和胶凝动力学的结果用于制备以PAM / PEI可交联聚合物为LCM的胶凝泥配方。产生的凝胶在高温高压储层条件下是热稳定的，这将导致井眼加强。