Research On Investment Benefit Evaluation And Decision Optimization For New Oil Fields

With the increasing scarcity of oil resources in Daqing and Shengli Oilfield, the oilfield development projects have been tunring to newly discovered oil fields, such as Tarim oilfield, Junggar oilfield and Ordos’s oilfield. Meanwhile, the newly oilfields becomes too difficult to exploit, and the exploration cost increase obviously. Thus, Oil field enterprise has to emphasize economic evaluation to gain more benefits at the expense of less cost. However, the existing research mainly on old oilfields, which could not solve the evaluation of investing benefit and newly oilfields’ investment decision-making effectively. For this envrionment, the geological knowledge is not sufficient and less historical data, so the traditional methods can not accurately predict the relationship between exploration investment and development investment, and the reserves and production of new wells. Moreover, the surface project and pipeline construction of new oil fields requires a mass of investments. Finally, the exploration and developing stages have not met the requirements of reserve-production ratio. Therefore, we proposed the concept of reserve replacement ratio constraints. According to the characteristics of new oil fields, the article constructs the evaluation methodology of investment results in new oilfield exploration, development and pipeline construction investment. Then this study establishes exploration, development and pipeline construction investment optimization model to make a plan for new oilfield of time, amount, area and capacity, which will provide theoretical support for the investment decisions of new oilfields. Among the research, we have taken five blocks of south Ordos’s oilfield as examples to explain the application process of investment benefit evaluation and decision optimization. The detailed research contents pressents as follows:Firstly, the study combines exploration and development investment returns evaluation with the current situations and problems of decision-making to illustrate background of selected topic and concluding realistic and theoretical significance of research, and puts forward research goals and innovation point.Secondly, this study summerizes current research situation relevant research status of oilfield investment evaluation and decision-making, and analyzes the problems when the research applied to the new oilfields.Thirdly, introduced use DEA model to calculate the efficiency of exploration and development investment and design a more suitable system of integrated traditional input-oriented CCR models, BCC models, FG models, ST models and the Super-efficiency DEA model under the assumption variable returns to scale and constant returns to scale, then using the model to evaluate the efficiency of the oilfield investment returns.Fourthly, Introduces hybrid multi-attribute decision making combining prospect theory for the problem of new oil outside pipeline solution optimization which has viable alternatives. According to expectations of decision makers for each attributes, the hybrid decision matrixs have been converting to loss decision matrix based on the reference point. With the alternative and decision expected weighted Euclidean distances, the Variable fuzzy recognition model are founded, then contains attributes weighting vector and membership degree is constructed. A cross-iteration solving approach has proposed to obtain the optimal weight vector and membership. Finally, considering the cumulative prospect value and membership of each program, calculate the value of the cumulative prospect value of the various options for sequence and selection making.Fifthly, the problem of new oilfield outside pipeline layout optimization which has no alternative, converted outside pipelines and pumping stations into a weighed direct graph establish a network optimization algorithm for optimal solutions of outside pipelines program, through the construction costs, operation and maintenance costs, the cost of pumping stations, operation and maintenance costs and energy costs between each pumping station.Sixthly, in order to maximize the net present value of investment for the purpose, a mixed integer programming model about medium and long term investment in exploration and development was established. Investment limit constraints, ground engineering construction constraints, reserve-production ratio constraint, output attenuation constraint and two important parameters using classification estimation were considered. In the end we take an oilfield in the southern Ordos as an example and plug the relevant parameters into the model, and then we can get the optimal results for the investment plan through Lingo.Seventh, two expanded problem about new oilfields’long-term investment optimization model has been constructed. Taking the block equilibrium constraints and reserve replacement rate constraints into account, the expanded model can be a flexible solution for the new oilfields’ exploration and development investment planning problem. We take an oilfield in the southern Ordos as an example and plug the relevant parameters into the model, and then we can get the optimal results for the investment plan through Lingo.Eighth, this paper design a short-term investment optimization model and algorithms as the long-term model does not fit the short-term problem. We also take an oilfield in the southern Ordos as an example and plug the relevant parameters into the model, and then we can get the optimal results for the investment plan through Lingo.Finally, the article makes a summary on the research contents and conclusions. Moreover, the places worthy of deep-going study are given directions and prospects in the future research.