Development And Application Of New Cleaning And Scale Inhibitor For Coalbed Gas Well Gathering And Transportation System

Mining coal-bed methane is the process of discharging the coal seam water,reducing the pressure of coal seam and releasing the natural gas in the coal seam.Produced liquid output and water treatment after qualified emissions to the natural environment will be scaled on the gathering pipelines and water treatment equipment.After scaled,pipelines flowing section and fluid transmission will be reduced.Seriously the pipelines will be blocked and facilities can not run normally,etc.So far,there have been a lot of researches about the scaling on the oilfield gathering lines,but do not include the coal-bed methane pipelines.At the beginning of mining coal-bed methane,it is necessary to draw the pressure water and a certain amount of pulverized coal will be produced.Therefore,the scale characteristics of coal-bed methane wells are different from those of ordinary natural gas wells.The thesis studies the mechanisms and influencing factors of scaling on coal-bed methane gathering pipelines based on the Xinzhou coal-bed methane wells to develop the anti-scale on the basis of studying the water quality and scale.As following steps:(1)Find out the potential factors of the scaling and sort the status and distribution of scaling to prepare for compounding anti-scale trough analysisof the geological situation,water treatment processes and so on about coal-bed methane wells on Xinzhou.(2)According to the?Analysis for oil and gas field water?,the water quality of 156 wells was tested,and taking the water treatment stations of Xinzhou region as the research objects,to prove the scale factors including Ca2+?Mg2+?Sr2+?Ba2+?CO32-?HCO3 and SO42-and analyze the types of scaling including calcium carbonate,strontium carbonate,barium carbonate and mainly calcium carbonate.(3)Select the representative scale and use Chemical titration,X-raydiffraction spectroscopy and other means to prove the main scaling that including calcium carbonate.(4)A total of 13 kinds of anti-fouling agents with small environmental impact were selected for the evaluation of single agent anti-fouling rate.PBTCA,HPAA and PESA,MA/AA were used to evaluate the compound Anti-fouling agent anti-scaling performance,get two excellent cleaning effect of anti-scale agent.(5)The two clean anti-fouling agent for comprehensive evaluation,and ultimately determine a variety of factors in the anti-scaling performance is still very good formula,and in the formula to add a special coal powder suspension agent,developed a A new type of cleaning and scale inhibitor for coalbed gas gathering and transportation system.(6)Choose the appropriate dosing equipment,According to the experimental scheme,the field experiment of No.1 water treatment station was selected.After testing,the new cleaning and anti-fouling agent developed a very good application effect,which solved the fouling problem of coalbed methane gathering and transportation system.but also confirmed the new clean anti-scaling agent of environmental protection.