Study On Gas Gathering Radius And Pipeline Network Optimization In Complex Regional Gas Field

The design of the gathering and transportation system is an important part of the development plan of the gas field.The gathering and transportation system is composed of gathering and transportation network and various stations.The cost of the oil and gas gathering pipeline network system usually accounts for 50% to 80% of the total cost of the gathering and transportation system.In the design process of the natural gas gathering pipeline network,gas-gathering radius directly affects the division of well groups.In order to ensure that natural gas is transported to the next station under the premise of meeting safety production requirements and technological criteria,it is necessary to study the gas gathering radius.In order to reduce the construction investment and the operation cost of the pipeline network,it is necessary to establish a pipeline network optimization model and a solution method based on the gas field wellhead distribution characteristics and production capacity.Goody GIS software is used to collect the study terrain data of the block.The geodetic coordinate system expressed by latitude,longitude and altitude is transformed into the space rectangular coordinate system.A three-dimensional topographical digital model of the study area is constructed by using the four-point spline function interpolation method with limited elevation data.Through horizontal and vertical segmentation,the 3D terrain data are discretized into regular finite nodes in order to store relevant information.Based on three-dimensional terrain,an ant colony algorithm and a roulette algorithm are used to establish a shortest path solution method for a three-dimensional surface.The result of the calculation example shows that the shortest path solved by the shortest path solving algorithm is 21.78% shorter than the original path.OLGA is used to study the influence of factors such as gas flow,pipe diameter,liquid content,outlet pressure and terrain on the gas gathering radius.A sensitivity analysis is performed.The research shows that the influence of the gas flow,pipe diameter and terrain on the gas gathering radius is significant.In the comparison of pipeline pressure drop between different pipeline undulation models under the same conditions,the M-type pipeline undulation model has the largest pressure drop.Under certain conditions,the gas flow and pipe diameter conditions of a typical M-type undulating pipeline and different gas collecting radius are calculated.According to the characteristics that the wellhead is distributed in strips and the pressure is mainly low and medium pressure,The branch-on-branch pipeline network is selected as the topology of the block gathering and transportation network by comparing the advantages and disadvantages of different pipeline network topologies.The shortcomings of the existing branched pipeline network optimization model with the total length of the pipeline network as the optimization goal are clarified.An optimization model for branch-and-branch pipeline network with the shortest flow distance of the pipeline network is proposed.It is solved by Dijkstra algorithm and Delaunay triangle network.The comparison shows that the flow distance of the pipeline network formed by this model is 17.1% shorter than that of the pipeline network formed by the traditional minimum spanning tree algorithm.This model makes up the inadequate of the traditional branched and related pipeline network topology optimization,which is greatly different from the actual one due to the neglect of pipe diameter.