Research Of High-efficiency Development Mode And Effect Appraisal For L Block In Offshore Oilfield

To achieve high recovery efficiency and high economic benefit, the reservoir must keep high speed drilling. However, the development reservoir is often in complex continental sedimentary environment with less development management experience. Therefore, the main problems in the offshore oil field development and challenges are urgently needed to further analysis, and perfect efficient system development ideas and technology must be established.Taking L block in offshore oilfield as research object, we fixed geological characteristics, and reveal oilfield water cut and production change rule. We summarized development experience of L block in offshore oilfield from many facts like the combination of development series of strata, injection-production well pattern deployment, water-injection to keep formation energy, proration measures to increase productivity and augmented injection allocation scheme, and so on. We put forward a suitable set of high-speed and high-efficient development mode for offshore conventional oilfield. Established a set of offshore oilfield development effect evaluation method, establish the development effect evaluation system and classification standard and evaluate the present phase of development effect.In this paper, the following results have been obtained.1) Oilfield water cut increase and production decline change with moisture content of the theory of change rule were revealed. Block water cut rising rate is convex type along with water cut, when the water cut is 40%, water cut rising rate reach peak value; displacement characteristics of the theory of recovery degree is concave type along with water cut; fluid volume production condition, the theory of natural decline rate is proportional to the water cut rising rate; actual output changes exponentially decreasing. And boundaries of different water cut stages are given.2) Put forward the suitable for offshore oil field of efficient development mode. Based on the single sandbody, reserve was recovered gradually from good to bad; relying on the "single sandbody well network optimization technology, horizontal well production-directional well water is taken. Early inject water to keep formation energy, while oil production rate maintains more than 3% for four years. Technique about extract and control water have been carried out special studies to block the low production and low efficiency wells in the aqueous phase.3) Established a set of offshore oilfield development effect evaluation method, including the single index evaluation and multi-index comprehensive evaluation. Established the offshore oilfield development effect evaluation system, optimizing the recovery rate, water flooding degree, water flooding reserves producing degree of reserves control, and water cut rise, decline rate, water rate, pressure level 7 indexes. Introduce the concept of evaluation coefficient, association the evaluation index of practical and theoretical value, and combined with the industry standard, single index classification boundaries are presented,6 indicators reached A level. Based on fuzzy comprehensive evaluation method, classification boundaries of development effect of the whole oilfield are given. L block finally scored 0.8042, higher than a standard limit (0.7419), reached A level of oilfield development.In the paper, results of similar offshore oil field development and production of job has important guiding significance and application value.