| Popis: |
Initiated in 2001, advanced water injection, as it kept improving, was adopted on an increasingly larger scale in Changqing in the Xifeng, Jing’an, Nanliang, Ansai, and Jiyuan oilfields in 2001–2009, covering an oil-bearing area of 1522 km2, geological reserves of 8.2×108 t, and a productivity of 1344×104 t, achieving good results. In our practice of overall advanced injection in the development of the Xifeng Oilfield, a higher rate of the capacity-building producers reach our designated productivity, with less decline than those in the same reservoirs that do not use advanced injection. Building an effective displacing pressure system, thus improving the efficiency of production in the ultralow-permeability Triassic reservoirs results in advanced injection produced responses as high as 71.7% of oil wells on average. We practiced in the Jing’an Oilfield the technological policy of water injection six months in advance, with an intake per unit thickness of 1.8 to 2.3 m3/d m. The injection timing schemes of the oilfield underwent three phases: delayed injection (more than half year after commissioning), synchronous injection, and advanced injection, producing different results. Practice shows that a reasonable technological policy at the initial stage of production enables a well to have a high productivity, which may decline more slowly and remain stable for a longer period of time. |
