Simulation Study On Drainage And Gas Recovery In Lateral Horizontal Wells

In the development of low permeability gas reservoir,the economic benefit of single horizon development is poor.Lateral horizontal Wells can mine two or more layers at the same time,which can improve the single well output and economic benefits of horizontal Wells.Using dual-lateral horizontal well water production gas field,as the development of gas Wells will appear different levels of water production,with two bottom double lateral well gas liquid two phase flow in a wellbore is more complex than the flow of the horizontal well,possible mutual interference between the dual-lateral will seriously affect the gas well production,an urgent need to study on dual-lateral horizontal well interference factors and drainage gas recovery technology research.Therefore,in this paper,first of all,the numerical simulation method of lateral Wells gas liquid two phase flow interference factors and the flow law of bubble simulation studies,and then use the results of numerical simulation to guide indoor physical model experiment,based on the lateral horizontal well flow characteristics of the lateral horizontal well pressure drop prediction model was established,combined with the lateral horizontal gas well production capacity model affecting the dual-lateral well production system and the main influencing factors of interference are analyzed in the design.The main work is as follows:Are simulated by using Fluent software lateral for export under the condition of the fluid through the lateral and vertical tube when the velocity field and flow field distribution,and the pressure difference between the space between lateral,lateral,entrance liquid composition and foam quality influence factors sensitivity analysis,indicates that the main factors leading to dual-lateral horizontal well interference and the flow law of bubble flow,on this basis,guide the indoor experiment.A set of visualized horizontal well simulation experiment device with adjustable outlet pressure of upper lateral was designed and built through simulation calculation.The total height was 6.5m,the horizontal section of two laterals was 2m,and the spacing between laterals was 3m.The upper lateral inlet is connected to the water tank,and the height of the water tank determines the static pressure at the upper lateral inlet.It can simulate the situation that the upper lateral outlet has pressure but does not contribute gas and liquid,and it is equipped with a gas supply system and a liquid supply system,etc.,providing conditions for carrying out the simulation experiment of drainage and gas production in horizontal Wells under different conditions.In order to observe the interference phenomenon between laterals,the dual-lateral simultaneous liquid supply experiment was divided into two laterals for separate liquid supply experiment to carry out the research.Combined with the pressure and flow data,the influence law of the upper lateral pressure,the pressure difference between the two laterals,the amount of inlet liquid,the concentration of foam drainage agent and other factors on the interference of the lateral well was analyzed in detail.Optimizing the lateral of the vertical section and horizontal section of horizontal well pressure drop model,based on lateral and wellbore flow characteristics,based on mass,momentum and energy conservation of dual lateral horizontal well is established the convergence of two phase flow pressure drop model,simulation calculation shows that flow pressure drop loss and lateral,lateral Angle horizontal section into the inflow velocity,flow rate,the vertical shaft inlet velocity,inlet quantity related to the factors such as wellbore radius.By comparing the experimental data,it is verified that the model can accurately predict the pressure drop loss of the confluence of the two-phase flow in the lateraling horizontal well.Based on the prediction model of pressure drop of b lateraling horizontal Wells and the productivity model of lateraling horizontal gas Wells,the case study was carried out to make a sensitive analysis of the interval between layers,production pressure distribution,gas-liquid ratio,etc.,so as to optimize the production parameters of dual-lateraling horizontal Wells and avoid the interference of laterals under the condition of ensuring the positive production of dual-lateraling Wells,so as to achieve high production.The study in this paper greatly enriches the related theories of drainage and gas production technology in lateral horizontal Wells,and has certain guiding significance for using lateral horizontal Wells to produce water and gas fields.