Preparation and performance evaluation of polyvinyl alcohol grafted polyacrylic acid for plugging

¹ Oil ＆ Gas Technology Research Institute Changqing Oilfield Company, X i’an, Chian
² National Engineering Laboratory of Tight Oil＆Gas Field Exploration and Development, Xi’an, Chian
³ Nanpu Operating Area, Jidong Oilfield, Tangshan, Hebei, China
⁴ Changqing Drilling Branch, CNPC Chuanqing Drilling Engineering Company Limited, Xi'an, Chian
⁵ Xi’an Key Laboratory of Tight oil (Shale oil) Development (Xi'an Shiyou University), Xi’an Shiyou University, Xi’an, 710065, China

^* Corresponding author: duweichao@xsyu.edu.cn

Abstract

Well-leakage is a very difficult problem in the process of drilling at home and abroad. At present, it mainly relies on the cumulative effect of plugging slurry to implement plugging regardless of the number of times and costs. Commonly used plugging slurry and plugging technology are difficult to guarantee the success rate and scientific of plugging malignant leakage, which has an extremely bad impact on the development of the petroleum industry. In this study, With polyvinyl alcohol and acrylic acid as main agents, a plugging material of acrylic acid grafted polyvinyl alcohol was prepared, and the influence of the composition of the reaction system on the gel state of the system was studied. Through a series of singlefactor experiments, the best formula for preparing the plugging material was determined, polyvinyl alcohol and acrylic acid (specific gravity 1:3) + crosslinking agent (0.1wt%) + initiator (0.3wt%). The gel plugging agent using above formula to prepare has good gel strength and suitable gel time, and has a good application prospect in solving the problem of lost circulation.