Study And Application Of Optimization Of Horizontal Well Drainage Gas Production

With the sustained development of China’s economic and the continuously increasing demand for natural gas, increasing efforts to develop gas field has become one of the im-portant tasks in China’s oil industry. The horizontal well shows a unique advantage in terms of economic, technology and production efficiency, it has become one of the important meth-ods to enhance gas recovery in China. However, with the continuous exploitation, the water production of gas well keeps increasing, the number of flooded wells increased year by year. Therefore, selecting an appropriate horizontal well deliquification technology and design scheme has a very important realistic significance for increasing and standing gas wells.This article put the H2well as the object of study, summarized the classical horizontal well deliverability equations both at home and abroad currently and wellbore pressure drop mathematical model, compared and analysed the differences between the various methods, derivating the deliverability equation of two-phase flow of gas and water which suits H2well, combined with vertical well deliverability equation of two-phase flow of gas and water and the concept of Joshi’s equivalent radius of vertical well. Researched the length of horizontal well, the thickness of gas reservoir, the anisotropy of permeability, WGR and the extent of damage of reservoir impact on horizontal well deliverability of two-phase flow of gas and wa-ter.Produced optimized selection program of horizontal well deliquification technology based on the theory of the windage distance comparative minimum and comprehensive-analyzing methods of definite quantity target. Through the field production research, opti-mized selected the deliquification technology of H2well. With the result of optimized selec-tion, the best deliquification technology of H2well is gas-lift deliquification technology.Based on the result of the optimized selected the deliquification technology of H2well, used fixed ground injection pressure method to design gas-lift deliquification technology of H2well. Researched the gas injection point depth of gas-lift deliquification technology, gas injection of H2well, and also got the parameter of each gas-lift valve. Combined with the de-liverability equation of two-phase flow of gas and water of H2well and relevanted wellbore pressure drop mathematical model, optimized gas-lift design parameter of H2well with nodal analysis method. Got the result of optimized of H2well. The economic gas injection is2×104m3/d, The best liquid production is82.1m3/d; The limit gas injection is4×104m3/d, The maximum liquid production is88.5m3/d; The best tubing size is62mm. Provided a reliable theoretical basis and reference value of horizontal well deliquification technology for H2well and the similar horizontal wells.