Experimental research of flow mechanism of near wellbore area of fishbone wells

Fishbone well is a special well type of multiple branches well,which has been widely used in oil industry.The complexity of hole structure of fishbone well increased the difficulty of its deliverability evaluation.Based on the principle of water and electricity similarity,a series of electric analogy experiments were carried out on fishbone wells to study the flow mechanism of near wellbore area.The potential distribution in near wellbore area of fishbone well were described and a detailed study were given on the productivity influential factors of fishbone well,such as the number of branches,the angle between branches and the main-bore,the length of the branches and the distance between branches and main-bore heel.Experiment results show that there is reciprocal interference between branch hole and main hole.Under the fixed length of branch hole and main hole,the productivity of fishbone well will increase with the increase of fishbone well branches,and the productivity of fishbone well will increase while the deviational angel increases from 0 to 90 degree,which will reach maximum when the deviational angel reaches 90 degree.