Rolling Development. Hexiwu Oilfield Comprehensive Geological Studies

Hexiwu oilfield in Langfang city ofHebei Province locates in the mid to north ofHexiwu structural zone, Langgu sag ofJizhong depression, and consists of 16 Tertiary sandstone reservoirs distributed on both sides ofHexiwu Fault. There are 13,960,000 tons of proved petroleum geologic reserves, 28.8 km2 proved oil-bearing area, and 160,000 tons of annul production capacity, and oil recovery rate of 1.15% in this oilfield. Until this project, producing geologic reserves was 10,410,000 tons, and 1,036,000 tons of oil has been produced, with recovery percent of 10%, oil production of 125 t/d, comprehensive water cut of 37.2%), and annul production capacity of 45,000 tons, oil recovery rate of 0.43%.In spite of some beneficial material foundation such as rich resources foundation, clear factors of main control distribution of petroleum and multiple bed sets, there are many unfavorable factors in Hexiwu oilfield incorporating crushed fault blocks, complex oil-water relations, and horizontal variety of reservoir in part of series of strata. This work set out to analyze contradiction, and to strengthen integrated geology study of exploration and development in the area by use of mature techniques including full 3-D interpretation and reservoir prediction means etc. under the dominant guideline of enhancing rolling development. On one hand, the old area was dissected. This study highlighted the integral research, deployment and implementation, and fully brought out latent potentialities in various aspect by combination of discovering new layer vertically, extending new blocks horizontally and tapping the latent power of old wells. On the other hand, new areas are expanded. By looking for the new productivity to take over the area piece, the aim of reserves increase and productivity boost synchronously was realized.According to the characteristics of high pressure reservoirs in the upper fourth member ofShahejie Formation, Such new fault blocks enriched with oil and gas as An28, An 56-12 and An 28-19 were discovered by Verifying earnestly the subtle faults which controls the reservoirs formation in the fault block from Xin 'an 71 to An 56, so the integral development was realized in fault block An28 and An56, and proved petroleum reserves reached 2,080,000 tons and new production capacity increased 82,500 tons. Both oil andgas were developed simultaneously- 0.65 km' oil-bearing area and 750,000 tons of geologic reserves were added to Block Xin'An 71,so this area has built 19,800 tons of production capacity of crude oil and 0.024 billion m of natural gas every year. At the downthrown block of Hexiwu fault, it started with study of regional conditions of forming reservoirs, realized the organism combination of exploration and development, and set up 15,000 tons of production capacity in that year. For Langdong area with rather crushed blocks, horizontal variety of layer and poor development benefits, this paper analyzed oilfield development statue deeply by combing dynamic and static data, carried out meticulous study on reservoir description, reservoir engineering evaluation and standards of logging interpretation. The implementation of transforming measures such as drilling, reperforation and reinjection boosted 28, 000 tons of the crude oil productivity in that year and made this old oil region fresh with vital vigor.After putting the research result into practice, 2.93 km2 oil-bearing area, and 3,990,000 tons of petroleum geologic reserves and 117,300 tons of production capacity were increased in this oilfield, so the crude oil production capacity in Hexiwu oilfield reached 160,000 tons because of the delightful study production.