Evaluation Of Polluted Water Reinjection Capacity In Puguang Gas Field

With the progress of science and technology and the increasing energy demand of naturalgas, natural gas production has increased year by year, and the produced water of gas field hasalso been increased. On the basis of reducing the cost of exploiting and protecting theenvironment, we also take the measure to reinject the produced water of the gas field.Puguang gas field water reinjection can not only solve the environmental problems, but alsoprevent water pollution, and save amount of money for the gas fields. But with the producedwater of the old wells rising and new production wells putting into production, the waterproduction has increased dramatically, and it is a seriouse problem to solve the reinjection oflarge number of produced water.To adapt to the needs of the development of the Puguang gas field, so we must monitorthe reinjection well and evaluate the reinjection capacity of the reinjection well of the gasfield.We can departure from the basic theory of fluid flow mechanics, combine with the actualsituation of Puguang gas field’s water injection well, then derive the water injection stablepercolation model of water injection wel in Puguang gas field; proceed from the reinjectionstatus quo and dynamic monitoring data of the reinjection wells, clarify the reinjection wellpressure and reinjection weight distribution characteristics; we can get the pressure andreinjection volume of the reinjection wells; we can also obtain the relationship of differentparameter in water injection process by this method, commonly used methods to calculate thereinjection volume of the reinjection wells include Volumetric method, Percolation methodand Numerical simulation method.On the basis of investigating and studying water reinjection status quo at home andabroad, by analysising existing reinjection well water injection current situation, monitoringof dynamic data and researching re-injection layer of Puguang gas field, we can get someresults:(1) on the basis of analysising geological conditions of Puguang gas field andcombining with the regional overview of injection wells,we can better understand thegeological conditions of the injection wells;(2) combining with dynamic monitoring data ofwater reinjection and wells dynamic analysis of water reinjection, it is able to draw wellinjectivity of water reinjection preliminarily;(3) calculating the remaining amount ofreinjection of reinjection wells by building And simplifing the model of the volumetricmethod;(4) on the basis of etablishing stable percolation model and thinking of the cumulativeeffect of injected water pollution formation, we can derive the waterflood model of injectionwells. The model can be well illustrated the law of waste water reinjection in the Puguang gas field, it can be better used in calculating maximum reinjection volume and depicting theimpact of the single-well’s injection capacity,to provide theoretical basis for Puguang gasfield.