疏松砂岩油藏水平井适度出砂开采携砂计算模型

针对疏松砂岩油藏水平井适度出砂开采方式下的压力及产量的求解问题,以水平井适度出砂生产过程中沿油藏到水平井生产段井筒为研究对象,采用现场工程法建立了出砂特征参数分析模型,在常规水平井筒压降求解公式基础上,进一步推导建立了携砂开采情况下水平井筒变质量流压降计算模型,联立了水平井向井流动态关系耦合求解模型,进行了实例计算分析,得到了井筒压降、流量及含砂浓度等重要参数的特征曲线,给出了水平段上沿程各流体参数非均匀变化规律,指出实际生产评价中应依据流量及浓度参数值计算水平井筒生产段上的危险沉砂点。该研究对疏松砂岩油藏水平井适度出砂开采方式最终产能评价及实际应用中的参数选择有指导意义。

Calculation model for moderate sanding production of horizontal wells in unconsolidated sandstone reservoir

To calculate the pressure and output of the horizontal wells in unconsolidated sandstone reservoirs, this paper takes the wellbore from reservoir to the production section of the horizontal well during sand producing as the research subject, builds the analysis model of sanding characteristic parameters by employing the engineering approach. Based on the solution formula for pressure drop of conventional horizontal wellbore, the deduces and establishes the calculation model for pressure drop of horizontal wellbore turning into mass flow during sand producing and the counting model coupled with the inflow performance relationship for horizontal wells. What's more, computational analysis is conducted by applying these three models and characteristic curves of such important variables as wellbore pressure drop, flow rate and sand density, etc are obtained. The heterogeneous regularity of the fluid parameters is indicated as well. It is proposed that the danger sand-settling points be calculated on the basis of the parameters of flow rate and density in real production and evaluation. The research is significant to evaluate the ultimate productivity of the production methods for moderate sand control of the horizontal wells in unconsolidated sandstone reservoir and select parameters for practical application.