Research On Gas Well Production Decline Law For Low Permeability Gas Reservoir

Packed columns have been broadly applied in the industry because of the high throughPut,low Pressure drop,excellent separation efficiency, great operation flexibility, small liquidholding.However,packed tower in large-scale industrial applications have "wall effect" and"amplification effect”, which makes the packed tower greatly reduce the efficiency of heat andmass transfer in large-scale industrial applications. The study showed that it is the velocitydistribution uneven caused packed tower "wall effect" and "amplification effect. The methodof set the separator unit and filler segment to the packed column can improve the uniformity ofthe flow field, weakening of the wall-flow effect "and" amplification effect ".It is difficult toaccurately measure the tower diameter, height size and segmental baffle height affect flowfield for the existing experimental means. With the computational fluid dynamics of theemergence and development, this provides a powerful tool for us.In this paper, computational fluid dynamics software Fluent as a computing platformin.Inorder to verify the reliability of the numerical simulation, numerical and experimental methodof combining a comparative study. In this process, combined experimental study with thecomputational fluid dynamics (CFD) method, the unit pressure drop and wall flow as an indexfor comparison with experiments. Using the technique of CFD Packed columns ofsingle-phase gas flow numerical simulation simulation calculation is carried out in threedimensional systems, expand to meet the convergence and quality of the conditions ofconservation, we can get the drawn of drop and full tower pressure distribution. by the Fluentsoftware.Using previous experience and the Euler Lagrange coordinate system studding twogas-liquid flow of the interior packed towe.Using the standardk model as the turbulencemodel, the Euler model as the model of multi-phase flow, porous media model as filling tosimulate the gas-liquid distribution pressure flow process..The results show that thesingle-phase gas-liquid two-phase pressure drop and experimental pressure drop error in4%to10%, simulation method is feasible and rationality.With height H, the tower diameter D, section height H and baffle plate distance Lstructure size many factors such as internal flow field of packed tower, the influence ofcomprehensive numerical simulation of large scale is difficult to implement, and therefore the orthogonal Latin square design of experiment. Misdistribution can be used to accuratedescription of speed field, so misdistributions as the index and9group representative levelcombination of the simulation are simulated. The results show that：①Through single factoranalysis can draw misdistribution increases with the height of H,tower diameter D,sublevelheight h and distance of the partition L. The sublevel height h in less than2000mmmisdistribution variation of small fluctuations, when h sublevel height greater than2000mmmisdistribution increases suddenly, the recommendations Break between500-2000mm, andthe separator distance L in the50-200mm.②Through analysis the numerical simulation of the9models, using range analysis effect on misdistribution，we can get the separator unit diameterpoor>tower diameter> sublevel height> tower③After analysis nine simulation by variance,the results show that the partition distance L, the tower diameter D have significant impact onthe misdistribution M, segment height h is significant for the general, tower height H towerhave a certain impact on misdistribution M.We use misdistribution as an indicator to thepartition unit distance L, the diameter of the column D and H sublevel height, multiple linearregression analysis of the quantitative relationship between them, and provide scientific basisfor the optimization design of packed columns.