Study On The Fractured-Vuggy Carbonate Reservoir’s Artificial Barrier Material For Controlling Bottom-water

The fracture-cavity carbonate bottom water reservoir in Tahe Oilfield is mainly developed in the vertical well mode.At present,the bottom water rise of the oilfield is serious,and the bottom water coning is unfavorable for oil and gas reservoir exploitation.In order to maintain efficient exploitation of the reservoir,bottom water treatment is required.Due to the high temperature of the reservoir,the large amount of salt in the formation water,and the thick oil layer,there are defects in the cementing and the construction of the gel to seal the bottom water.In response to this problem,this paper proposes to construct a chemical separator system by two methods of resin particle thermal blocking and monomer underground polymerization.The paper preliminarily screened the self-adhesive resin particles that meet the temperature and salt tolerance of the Tahe oilfield reservoir,and controlled the polymerization time of the monomer,the distribution of the barrier material,the oil solubility control of the barrier,the polarity control of the barrier,etc.It is required to construct a monomer system for subsurface polymerization including 87.9 styrene,10% polar monomer(vinyl acetate),1%crosslinker(divinylbenzene),1% initiator(tert-butyl peroxybenzoate)and 0.1% retarder(peroxy catechol)by means of a preferred retarder,emulsifier,crosslinker and polar monomer.The results show that the polymerization time of the system at 130 °C is 5 hours.The polymerization product has good stability in oil and has good adhesion to formation rocks.The system was formulated into an oil-in-water emulsion by using an octadecyltrimethylammonium chloride solution with a mass fraction of 0.1%,and was polymerized at the oil-water interface to form a artificial barrier.The research results have a certain guiding effect on the sealing of bottom water in fracture-cavity carbonate reservoirs.