致密油藏分段压裂水平井产能模型研究

A Study on Production Analysis Model of Multi-Fractured Horizontal Wells in Tight Oil Reservoirs

摘要: 致密油藏渗透率低、储层物性差，因此需要采取水平井分段压裂技术进行开采。为此本文建立了致密油藏分段压裂水平井产能模型，人工裂缝基于离散裂缝模型进行降维处理，使用伽辽金有限元方法对数学模型进行求解，最后，通过某油田实例研究验证了本模型的可靠性与实用性。研究结果表明：生产压差越大，产量和累积产量也越大，但压差过大会导致原油脱气，因此在实际生产过程中，应合理控制生产压差；基质渗透率越大，产量和累积产量也越大；裂缝导流能力越大，产量及累积产量越大，但随着压裂缝导流能力的增加，产量增幅逐渐变小。研究结果可为致密油藏产能分析提供理论支持。

Abstract: Due to the low permeability and poor reservoir properties in tight oil reservoir, multi-fractured horizontal wells technology have become an efficient way to produce from this kind of unconven-tional reservoirs. A production analysis model of multi-fractured horizontal wells in tight oil re-servoir is established in this paper, the dimension of artificial hydraulic fracture is reduced based on the discrete fracture model, and the solution is obtained by Galerkin finite element method. Eventually, a field example verified the reliability and practicability of the model. The result shows that the production and cumulative production will increase with the producing pressure drop increases, at the same time, too large producing pressure drop will cause the degassing process of oil, so the producing pressure drop should keep a reasonable level in the actual production. The bigger the effective permeability of the matrix is, the greater the production and cumulative pro-duction is. The bigger the conductivity of artificial hydraulic fracture is, the greater the production and cumulative production is, however, the growth rate of production and cumulative production will decrease with the conductivity of artificial hydraulic fracture increases. The results achieved can provide theoretical basis in the study of production analysis for multi-fractured horizontal wells in tight oil reservoirs.