Using Digital Core Technology To Simulate Gas-Water Relative Permeability Under High Temperature And High Pressure

Gas water relative permeability data is an important basic data in the development of gas field.However,it is time consuming,costly,difficult to operate and the success rate is low about the simulation of high temperature and high pressure formation in real gas water phase permeability test.So the permeability is generally water gas according to the standard SY/T5345-2007 under laboratory conditions using compressed air or nitrogen and water or brine by steady-state method or non-steady state core displacement experiment,without considering the effects of formation of high temperature and high pressure,there is a big difference with the actual conditions of seepage stratum conditions.Recent years,the digital core technology has been used more and more in the petroleum industry,compared with traditional laboratory core experiments,the digital core technology have many advantages like:simulation time consuming less,convenient to obtain data,the same core can be simulated in different temperature under different pressure synchronous and repeatable.Conventional digital core simulation technology has not been simulated under the condition of high temperature and high pressure,due to rock buried deep in the ground,common simulation environment is not in conformity with the actual engineering practical.Therefore,considering the high temperature and high pressure model is established under the condition of displacement and seepage together is particularly important.Based on the above consideration,this article independent build a set of establishing digital core method to simulate gas water seepage flow under high temperature and high pressure condition.Combining with the laboratory data,demonstrates the actual digital core simulation instead of lab test feasibility.This research has got the following conclusions:(1)AVIZO software is used to calculate petrophysical parameters,data is consistent with the actual test results can be obtained.When the computer is short of memory requirements,permeability can be segmented to calculate the arithmetic mean of the reentry after;(2)To repair the digital core process,requires a combination of import COMSOL manual repair after the feedback information,because otherwise it is difficult to import success;(3)There is a difference between the results of the experimental results and the simulation results,which are obtained under the conditions of normal temperature and normal pressure and high temperature and high pressure,at the isotonic point,under the condition of high temperature and high pressure the water saturation is lower and the relative permeability is lower.Compared with the normal temperature and atmospheric pressure,the two-phase infiltration ares is more narrow under the condition of high temperature and high pressure;(4)The simulation results of two different conditions are consistent with the experimental results:The location of the isotonic point is basically the same,the irreducible water saturation is the same,the relative permeability of the gas phase is the same as that of the irreducible water saturation,and the residual gas saturation is the same;(5)A feasible simulation method of high temperature and high pressure is established.Only the rock porosity and permeability parameters,fluid at a certain temperature under the pressure of the physical parameters and the residual water,residual gas saturation and other basic data,and then set the appropriate boundary conditions,researchers can calculate the relative permeability curve of the rock.