The Study And Application Of Chemical Water-shutoff For Horizontal Well In Liaohe Oilfield

As an important technical development of complex reservoir, horizontal well development technique has been widely useing in major oil fields, for lacking more efficient water shutoff technology, A large number of horizontal wells face the problem of high water cut and low effective production, batch production or shutting in, which has influenced seriously the normal production of horizontal wells and the sustainable development of oilfield.According to the effluent characteristics and reservoir conditions of horizontal wells in Liaohe oilfield, three types of water shutoff agent systems were designed and researched about their influence factors, suitable conditions and plugging performance evaluation:(1)The plugging agent of LH-Ⅱ liquid bridge plugged the water breakthrough of A point with the function of temporary shutoff and oil reservoir protection, which can adapt 180℃ and endured the breakthrough pressure gradient of 9.65MPa/m, and break completely more than 200℃.(2)Annular casing packoff material forms the chemical sealing material and isolate the annulus region between the screen pipe and the wall of well with the help of horizontal wells chemical injected technology Tubes. it can bear 280℃ after gelling and restore the permeability more than 90% on the condition of injecting steam.(3) Secondary Crosslinking water shutoff agent is mainly used in deep formation plugging, and reduces the impact of block steam channeling, the gel strength can reach 10000mPa·s above, and plugging rate is more than 92%.(4) A statistical analysis of the characteristics and location of Liaohe horizontal wells, combined with plugging agent type, iquid bridge and outside annulus Casing Packoff, two kinds of water plugging technique, had been carried out and obtained good effect of increasing oil, provided technical support for stabilizing production and controlling water in horizontal wells in liaohe oil field.