The Development Potential Evaluation Methods Of Su 5 Block For Low Permeability Gas Reservoir

The low porosity,low permeability and high water saturation of low permeability gas reservoirs induce many factors affect the computational formula of capacity,and the cornventional productivity formula can't be applied to calculate and analyze it.Sulige gas field is one of china's ultra big gas field and principal gas field of the"Western Gas Transport Eastward" project.Sulige gas field reservoir geologic condition is very complicate,belong to low pressure,low permeability,low abundance,large area distribution and lithology gas reservoir.There are great difficulties to develop,which mainly show as follow three aspect.Firstly,gas well production show that formation energy supply not enough,well head pressure decline quickly,stabilized production period is short.Secondly,well control periphery low permeability zone has certain recharge capacity,gas well production rule predication is difficult at low pressure.Thirdly,single well controlled reserves is low,single well benefit is bad.This paper use analysis of core experimental to carry on a further research on stress sensitivity,flow characteristics and the influence of deliverability.And then analyse the development potential of Sulige gas field.Obtain achievement as follow six aspects:? According to the geology and development characters of reservoir in Sulige gas field,analyse the production performance of Su5,Tao7 and Su59 blocks.It founds that the decrease of output and pressure have the character of "two section type".They decrease fast in initial production.and tend to be stable in intermediary and later stage.? The permeability stress sensitivity tests of rock specimen in Sulige gas field were worked,and found that there's very slightly stress sensitivity in low permeability gas reservoir.The cutting point of permeability variation is 17MPa.The loss rate of permeability stress sensitivity and the extent of damage are very strong.? The starting pressure of low-permeability gas reservoir core was tested in the rock flow experimental equipment,using 4 cores in Sulige gas field.According to analyzing the experimental results,the starting pressure has strong effect on cores.In the condition of high bound water.the true starting pressures of the 4 cores are increase with the bound water saturation.? The productivity formula was worked out which considering the permeability stress sensitivity,conventional and water-blocking starting pressure,or both the permeability stress sensitivity and starting pressure.And calculate deliverability on representative well in Sulige gas field.? The transient deliverability formula was worked out which considering the starting pressure,or both the starting pressure and permeability stress sensitivity.And calculate deliverability on representative well in Sulige gas field.? Using Su5 and Tao7 blocks in Sulige gas field as example,according to the physical truth of geologic characteristic,rock and fluid property of the blocks,we choose the three-dimensional two-phase black oil model and emulator of E100 model in Shlumberger company to research the exploit thelatent capacity in Sulige gas field.