| The Fuyang layer, in Changyuan Peripheral of Daqing Oilfield, belongs to extra-low permeability reservoir, proved to have a storage of 6.3×102 million tons. From the water injection development of the experimental zone in 1982, it has been established into a big oil field with a certain scale of production. But so far, a considerable number of blocks in this area have been invested in the inefficient state. At the same time, new proved storage is becoming worse and worse than ever before and the handicaps of low permeability, low abundance and low mobility becomes poorer, which increases the difficulties of the development. Therefore, improving the efficiency of the developed blocks while put the unused blocks into production as soon as possible means a lot to the sustainable development of Daqing Oilfield.By conducting SEM, CT scanning, rate-controlled mercury experiments, this research studied the distribution regularities of pore structures such as pore radius, throat radius, pore-throat ratio, coordination number, tortuosity and shape factor, then got the regression equation between permeability and pore structure parameters; Using NMR, this research studied the movable liquid saturation of various classifications of permeability by measuring the T2 relaxation spectrum; Aiming at the reservoir’s character, this article measured the relative permeability curves of porous medium and double medium and researched their non-Darcy flowing rules; Researched the flushing efficiency by conducting flooding experiments of various permeability classifications; Researched the water-flooding developing limits based on the result of pore structure, NMR movable fluid saturation and threshold pressure. This article, based on the research of pore structure, movable fluid saturation and threshold pressure, showed the permeability limits of water-flooding development, which had a great significance for the oilfield classification and subsequent development. |
PDF Full Text Request