Abstract
The Weizhou X low-permeability reservoir is an offshore reservoir, with
a permeability ranging from 0.58×10 -3μm
2 to 470.05×10 -3μm
2, showing strong heterogeneity. In the subsequent
water injection development, good results were not always obtained. The
main problem was that during the water injection process, the injection
pressure increased significantly, resulting in low water injection
volume and low water injection efficiency, which could not maintain
long-term effective effects on production. Improvement, it is difficult
to replenish energy in the formation. Through the analysis of
pore-throat structure, water quality compatibility and sensitivity, it
is clear that pore-throat blockage is the main reason for low water
injection efficiency. Aiming at the present situation that the scaling
matter is mainly calcium carbonate, a solution to soil acidification and
plugging removal was proposed, and the water injection damage of the
actual reservoir was simulated. The indoor acidification experiment was
carried out, which showed that the effect of acidification on the
transformation of the reservoir was good, and the average rate of
transformation is 129.21%. Suggestions are put forward for the
effective development of Weizhou X low-permeability reservoirs, the
economic benefits of development are improved, and guidance is given for
the enhanced injection measures of low-permeability oilfields.