Study On The Law Of Effluent And The Criterion Of Effusion In Sulige Gas Well

At present,the Sulige Gasfield has entered the large-scale construction and development stage,and the gas production rapidly expanding.It became the largest Gasfield of Changqing.With the development of gas reservoir,effusion wells gradually increased in Sulige Gasfield.By the end of2014,effusion wells account for about40percent of the total wells.The gas reservoir contains many layers of Sulige Gasfield,and each one is very thin.In order to make more efficient development of this area,the mechanical packer separated fracturing commingled production integrated string technology was adopted,and how to discriminate effusion wells had become the important problem because the common methods were not applicable due to the application of downhole choke.Inaddition,the surface flow process of Sulige GasField is simplified, the lack of measured water production rate and bottom hole producing pressure,which caused the conventional method even harder to weighting liquid loading level accurately.Building the liquid loading predictive model suitable to effusion wells in Sulige GasField to solve the problem.It had a certain guidance and reference significance for the development of the whole GasField and even other water-producing area of low-permeability GasField to analyze liquid loading level.In view of the above questions, a new method is proposed in this paper,taht is applicable in Sulige to deal with this problem. The new method considers factors including dynamic reserve,production proration and Gas offtake(the gas recovery per year)etc. Analyzed,in detail,the characteristics of the casing pressure when the gas well without fluid accumulation,and the slope of casing pressure under different liquid loading rates.This technique is applied to Sulige Gasfield well,and the method to determine annular liquid loading level is also listed.Based on the method of weighting liquid loading level,we got a new prediction method of tubing effusion by making the tubing pressure and the casing pressure as input data.So we obtain a model to calculate the fluid volume of the effusion wells in Sulige GasField.By analyzing the model,combining the analysis of theoretical calculation and measured data statistics,we establish a new technology to estimate liquid loading.This technology not only can judge the liquid loading level but also can calculate the amount of fluid in the wellbore, and provides an important basis for prevention of wellbore fluid and the post drainage gas recovery work.