Optimal Layout Of Oil-Gas Gathering And Transportation Pipeline Network Considering Operating Expenses

In oilfield construction project, oil-gas gathering and transportation system which investment mainly consists of the construction costs of pipelines and intermediate stations and the expenditure of daily operating is the major construction. The original investment for pipelines and intermediate stations usually takes up 60 to 70 percent of the whole oilfield construction costs. And the operating pipeline network expends massive heat and power. It is significant to economize investment, save energy and increase the social and economical benefit by the reasonable pipeline network optimization design.Design of the pipeline network which goal is minimizing investment contains ascertainment of the pipeline network layout and the parameters of pipes. In this thesis, based on the summary of many optimization researches and achievement of oil-gas gathering and transportation pipeline network, an improved optimization technique on basis mathematical model is proposed to lay out the pipeline network optimally with consideration of both oil well scattering area and operating parameters. It improves the mathematical model with the goal function of minimum the synthetical expenses per year of pipeline network and build up a model with design variables of the relations of oil well and station, the intermediate stations position and the pipe diameter.The summation of pipeline construction investment and operating expenditure is called the synthetical expenses. Pipe diameter preference is included in the process. Thus diameter and length of pipe connect construction investment, heat consuming and power consuming so as to make this optimization design feasible within the temperature and pressure constraints. Due to plenty of discrete and continuous variables, optimization with genetic algorithms combined with simulated annealing which has better global search ability is used.An instance which is designing of a multilevel star style network calculated by an optimization program written in Matlab language indicates that the model and algorithm in this thesis is superior to the present methods. It makes the synthetical expenses of oil-gas gathering and transportation pipeline network minimum and compares the synthetical expenses of star type network and tree type network. Results manifest this algorithm accuracy and advantage. It provide certain merit and meaning for optimization design of oil-gas gathering and transportation pipeline network.