Indoor Evaluation Of The Blocking Agent For The Development Of Cavernous Carbonate Reservoirs

The Ordovician carbonate reservoir in Tahe Oilfield has entered the middle stages of development.After the water entering the oil well,the water content rises rapidly,which leads to a large natural decline in oil production.Therefore,relevant water blocking measures must be taken to slow the rate of increase of water content.The geological conditions in this area are complex,with ultra-deep,high temperature,high salinity and strong heterogeneity.The space of the reservoir is diverse.In this paper,the research on cave-type reservoirs has proposed two different blocking system,including 4 sets of blocking agent and 1 kind of hard temperature-sensitive adhesive particles.This thesis mainly uses experimental research methods,supplemented by theoretical research methods.Firstly,two kinds of blocking system were proposed,which were vitrified microbead composite blocking agent and polymer synergistic curing particle blocking agent;then,for the former,through the proportion optimization,four specific formulas were constructed;then the formulation of the latter was determined.Finally,a large-scale water shutoff and profile control experimental instrument was used to construct a sand-filled pipe experiment with large-diameter and multi-fracture tunnels to simulate the reservoir and evaluate the blocking agent.Studies have shown that the curing temperature of microbead composite blocking agent is 140 ° C,the curing time is 25-30 hours,the blocking rate can reach 50%,and the breakthrough pressure is about 4-9MPa.The curing temperature of hard particles is 130-140 ° C,and the time is about 5 hours,and suspended time over 150 days,the strength after curing is about 5-6 mm.This study provides effective theoretical support for the water-blocking process measures of cave-type carbonate reservoirs in Tahe area,which has certain guiding significance for efficient development of oil fields and enhanced oil recovery.