Research on the rheological and flow characteristics of a supramolecular gel in fractures

摘要

Loss circulation is one of the major concerns in drilling and well construction. An effective way to control drilling fluid loss and strengthen the wellbore is to plug fractures and holes with loss circulation materials. In this work, a hydrophobic association supramolecular hydrogel GP-A developed by n-dodecylacrylamide, methacrylamide and 2-acrylamide-2-methylpropylsulfonic acid was proposed as a potential lost circulation material for malignant drilling fluid loss. The results show that the initial decomposition temperature of GP-A was 172 degrees C, and the flow characteristics conform to the Herschel-Bulkley model with yield stress. Microstructural analysis shows that GP-A gel with a 3D spatial network, and hydrogen bonds between branched chains form a dynamically recoverable structure. Based on POLYFLOW, the Phan Thien-Tanner model with viscoelastic parameters was used to simulate the viscoelastic flow characteristics of the fluid in fractures. The higher the concentration is, the greater K, and the higher the inlet driving pressure, while the nonlinear relationship between the driving pressure and the gel slug length is evident. The introduction of supramolecular gel polymer as a loss circulation material is an innovative research topic, which provides a new method to simulate the flow of polymer fluid in fractures.