Development and performance test of an expansive particle temporary plugging agent

Abstract Addressing the problems found in some wells in the carbonate reservoirs of Tahe and Shunbei blocks, such as wide natural fractures and large leakage, an efficient temporary plugging agent is developed to effectively seal up large fractures and leaky wells without affecting the flow path after acid fracturing. The temporary plugging agent is prepared by crosslinking an organic zirconium crosslinker with starch-grafted polyacrylamide. Among the materials, starch-grafted polyacrylamide shows good viscoelasticity, water absorption, expansion, and degradable properties; an organic zirconium crosslinker can improve the sealing effect. The temporary plugging agents produced from the two-boast have good performance in water absorption and expansion, temporary plugging pressure, and degradability. Experimental tests evaluated the developed expansive particle temporary plugging agent’s performance. According to the results, the particle size of the temporary plugging agent can expand 4 times larger; its final degradation under formation conditions reaches 99%. A larger plugging agent particle size and a higher concentration of the plugging agent can increase the plugging pressure. The plugging pressure can be as high as 15.5 MPa at a 5% concentration of the plugging agent with a particle size of 2 mm, which fully meets the needs of temporary plugging fracturing on site.