煤层注CO_(2)驱替CH_(4)影响因素试验研究

Experimental study on influence factors of CH_(4) displacement by CO_(2)

为明确多因素耦合对CO_(2)驱替CH_(4)过程中CH_(4)产出与CO_(2)封存效果的影响特征,开展不同注气温度θ、压力P和煤样含水率W条件下注CO_(2)驱替CH_(4)试验,研究分析不同条件下CH_(4)产出率η和CO_(2)储存率ξ变化特性,基于响应曲面法,构建η和ξ二次回归响应曲面模型,分别考察注气温度A、注气压力B、含水率C对η和ξ的单独影响及各因素间的交互作用。结果表明:η随θ和P增加而增大,随W增大而减小;ξ随P增大而增大,随θ和W增加而减小。影响因素中A、B、C均为η的显著项,B和C是ξ的显著项,一次项对η和ξ影响程度均为C>B>A;交互项对η的影响程度为BC>AC>AB,且AC和BC交互作用显著,AB交互作用不显著;交互项对ξ的影响程度为AB>AC>BC,且AB和AC交互作用极显著,BC交互作用不显著;4组η和ξ编码区间外试验值与模型预测值平均偏差分别为3.64%、2.605%。

In order to study influence of multi-factor coupling on CH_(4) production and CO_(2) sequestration effect in the process of CH_(4) displacement by CO_(2),displacement experiment was carried out under conditions of different gas injection temperature(θ),pressure(P)and water content of coal samples(W).Variation characteristics of CH_(4) output rate(η)and CO_(2) storage rate(ξ)under different conditions were researched and analyzed.Then,ηandξquadratic regression response surface models were built based on response surface methodology,separate influence of gas injection temperature(A),gas injection pressure(B)and moisture content(C)onηandξand interaction between each factor were investigated.The results show thatηincreases along with increase ofθand P,while decreases with that of W.ξincreases with increase of P,while decreases with that ofθand W.Among all influencing factors,A,B,and C are significant terms ofη,B and C are those ofξ,and influence degree of primary term onηandξis C>B>A.That of interaction term onηis:BC>AC>AB,and the interaction between AC and BC is significant,while AB interaction is not.Influence degree of interaction term onξis AB>AC>BC,and interaction between AB and AC is extremely significant,while that between BC is not.The average deviations between experimental values outside coding interval ofηandξof the 4 groups and predicted values of the model are 3.64%and 2.605%,respectively.