STUDY ON SELECTIVELY PLUGGING GAS WITH SLIGHTLY CROSS-LINKING GEL FOAM IN LAB

Aim at the serious gas channeling of Bo Sea SZ36-1 oilfield, the high ratios of oil to gas, and the situation making oil well can not produce normally, choose slightly cross - linking gel foam system used in preventing production well from occurimg gas channeling. Through the selection of the static foam experiments, the best system of slightly cross - linking gel foam was composed of 0.8% HAMP whose molecular weight is six million as stabilizator, 0.5% alfa- olefine suffonate (C14- 16- AOS) as foamer, 150~200 mg/L Cr3+ as cross - linking agent. The experiments on effect factors indicate that pH value and temperature have little effect on the quantity of foaming and half - life when pH value changes from 5 to 11 and temperature is not more than 90℃, that the foam becomes better when the pressure goes up, that its stability is bad before gelled but its stability becomes very good after gelled and its half - life is much longer than that of polymer - enhanced foam,that the stability of foam decreased when a little oil is added before foaming, while the stability of foam is hardly affected when some oil is added after foaming. Dynamic experiments show that the foam can selectively plug hydrophilic core with different permeability well, but it is difficult to plug hydrophobic core,so the gel foam can selectively plug formations with the wide difference in oil saturation. The experiment effect shows the application perspective of slightly cross - linking gel foam is wide in gas shutoff because it has advantages of foam and colloid.