Study on High Temperature Delayed Crosslinking PAM Gel LCM

Abstract

A hot melt adhesive delayed initiator was developed making use of the thermoplastic property of hot melt adhesive. This delayered initiator was then used to develop a high temperature delayed crosslinking polyacrylamide (PAM) gel lost circulation material (LCM) using acrylamide and N, N'-methylene bisacrylamide as the monomers. The high temperature delayed crosslinking LCM was characterized by IR spectroscopy and SEM, and its gel-forming time, plugging capacity and high temperature resistance were all tested. The experimental results showed that the initiator was successfully coated with the hot melt adhesive. Compared with the blank sample, the high temperature delayed crosslinking LCM can effectively delay the gel forming time, making the gel forming time adjustable between 1 h and 4 h. The LCM has excellent plugging performance, it effectively plugged a fracture of 4 mm at elevated temperatures under 700 psi or higher pressure working on the fracture. The LCM also has high temperature resistance, after hot rolling 5 d at 150 ℃, only 5% of the gel was broken. This high temperature delayed crosslinking gel LCM can be used to effectively stop severe mud losses to fractured formations.