Study On Gas Drilling Dust Removal Technology

Gas drilling technology has been widely used and developed in China in recent years,and it has many advantages such as greatly increasing the speed of mechanical drilling,controlling well leaks,protecting and discovering oil and gas reservoirs,shortening the drilling cycle,and reducing costs.It has become one of the important techniques for developing low-pressure and low-permeability reservoirs,cavities and cracks,and greatly increasing mechanical speed and increasing efficiency.The biggest problem for domestic gas drilling is environmental protection.The existing dust removal methods in China are not satisfactory.Dust and water mist pollution are serious.With the continuous improvement of environmental protection requirements,the existing dust removal methods can no longer meet environmental protection requirements.Therefore,it is urgent to study the new dedusting technology to solve the environmental pollution problem caused by the current gas drilling debris discharge method in China,and further expand the application scope of gas drilling.Based on the research of domestic and foreign literature,this paper,combined with the drilling situation of gas drilling,carried out the research on the breaking and moving mechanism of gas drilling debris.Through the analysis of the crushing collision velocity of rock debris,obtained the return of gas and debris carrying rock in the borehole.The rate is generally above 15m/s.Whether rock debris particles can be impacted and broken is not only related to the collision speed,but also related to the impact angle.Theoretical and experimental studies on the particle size distribution in the process of upper and lower return of debris have been carried out,and the distribution ratios of different particle sizes have been obtained.Under normal circumstances,the particle size of debris returned from gas drilling wells is 0.015 to 9mm,and the median particle size is 0.02 to 1.05 mm.If there is a collapse in the well,the maximum particle is 30 mm,and the mass concentration of the debris returned from the gas drilling well is between 330 and 900 g/m3.Based on the theoretical results,the separation technology and dedusting performance of gas drilling debris were studied,a new dedusting system was developed,which consists of two stages.The classification efficiency and maximum treatment capacity of the dust removal system and the overall purification efficiency are studied.Through theoretical research and process design and the development of a new type of dust removal system,the gas drilling and dust removal technology formed has been studied in situ in the GK003-5 well,and the data of the entire trial process has been recorded and the results evaluated.The results show that the purification effect of the gas drilling fluid is very obvious after the separation system.The concentration of the exit particles fluctuates between 0.05 and 0.07 mg/m3,which verifies that the process and the dust removal system are very good.