Well Stimulation Evaluation Index System

Liaohe Oilfield was put into large-scale exploration and development in 1970, its production broke through 10 million tons in 1986, making it the third largest oilfield in China. Historic peak production of 15.52 million tons was achieved in 1995. At present, Liaohe Oilfield is in its middle and late stages of exploration and development, which means it is more difficult to keep a stable production. In recent years, a series of stimulation measures such as reperforation, water plugging and so on have been taken in different parts of the field to improve oil production and relax the natural depletion. However at the same time, investments for measures taken have increased production cost and for some blocks economic benefit is weakened. Some measures have trace or no result of stimulation, leading to a entire decrease of economic benefit while oil production increases. A study and analysis on input of measures and stimulation results of oil producers in Liaohe Oilfield in recent years has been conducted in the paper. A System of Evaluation Indices for Oil Well Stimulation Measures in Liaohe Oilfield has been structured based on relevant theories of System of Economic Evaluation Indices for Oil & Gas Exploration Projects and Mode of Economic Evaluation for Oil & Gas Exploration Projects. Method of Increment used in economic evaluation for modification projects has been adopted for evaluations on benefits of measures. The system shows the development results brought by measures as well as economic benefit. Meanwhile, it also combines modes of quantitative evaluation and economic indices evaluation, determines the two main components for the system of evaluation indices on benefits of measures, that is, technical index and economic index. Major indices include reserve, remaining oil, recovery, cementing quality, incremental oil from measures taken, revenue from measures, measure increment input & output ratio, valid period of measures, duration of investment return of measures, validity of measures and economic efficiency, etc. Through scientific analysis and studies on stimulation measures taken in different geologic blocks, the most proper measure based on geologic condition under certain economic policies are found to guide and manage oilfield production so as to decrease risks of investment and improve economic benefit, there fore to maximize the benefit.