摘要
油藏注水开发过程中,粘土水化膨胀,水不配伍产生化学沉淀,水中携带大量悬浮物、微生物及其代谢产物都可污染油层,堵塞渗滤孔道。本文结合胜利油田某些油藏注水实例,介绍岩心阳离子交换量、注水造成的粘土水化膨胀和迁移、水不配伍造成的化学沉淀和水中悬浮固体堵塞等对油藏污染程度的试验方法、研究结果和结论。
After having been water-flooded over a long period, the petroleum reservoirs may be polluted owing to the blockage of oil/water canals. In this paper the reservoir pollution in some oil fields in Shengli is studied through core-flow tests in relation to the cation exchange capacities (CECs) of cores, hydration, swelling and transferring of clay particles, chemical precipitates formed by imcompatible waters, and suspended solids in injection waters. The permeability decrease of cores is more significant when their CECs are higher and their permeabilities themselves are lower. For Gudong Oil Field, Shengli, sea water would be a better choice than Yellow River water, though both are well compatible with the produced formation water. By using a specially prepared artificial water it is shown that chemical precipitation causes more serious permeability decrease when the permeability itself, thus the pore size, is less and the produced formation water is superior to Yellow River water for injection purpose. The maximum allowable sizes of suspended solid particles in injection waters are calculated from the permissible decrease in water-absorbance indexes of given stratum zones on the basis of Purcell's permeability equation and water absorbance index expression with suggestion that the solid paticles with size more than 1/6—1/7 of that of pores in the reservoirs would produce canal blockage.
出处
《油田化学》
CAS
CSCD
北大核心
1991年第2期112-117,共6页
Oilfield Chemistry
