TITLE:
Research on Water Sensitivity and Velocity Sensitivity of Loose Sandstone Reservoir in China Offshore Oilfield
AUTHORS:
Dengfei Yu, Ming Long, Yuejie Wang, Qin Huang, Jingling Li
KEYWORDS:
Reservoir Damage, Water Sensitivity, Velocity Sensitivity, Loose Sandstone, Seepage Mechanism, Clay Minerals
JOURNAL NAME:
World Journal of Engineering and Technology,
Vol.10 No.2,
May
13,
2022
ABSTRACT: Aiming at the development characteristics of Bohai P oilfield, formation mechanism of reservoir damage was analyzed by mines of mineral composition, micro-pore structure, and seepage mechanism. Microscopic petrological observations and laboratory core experiments show that the content of clay minerals such as the Imon mixed layer and kaolinite is high with high porosity and good pore roar structure; the water sensitivity is medium to strong, The lower the salinity of injected water, the greater the drop in core permeability; the velocity-sensitive damage is strong, and permeability increases with the increase in flow velocity, and a large number of particles are observed in the produced fluid under the microscope. Aiming at the contradiction of velocity sensitivity between core permeability increase and the permeability decrease near the wellbore, the velocity sensitivity seepage model of “long-distancemigration and blockage near the well” is proposed, and the permeability and formation distribution formula are deduced. The calculated value is close to the test value of actual pressure recovery test. The research results of water sensitivity and velocity sensitivity provide important guidance for Bohai P oilfield to improve production and absorption capacity and reservoir protection.