Abstract Geothermal energy resources are highly available but under-utilized throughout the world. Previous studies have sought to understand reservoir response to geothermal production and optimize production rates to maximize lifetime profits of geothermal reservoirs; however, these studies largely overlook the uncertainty in subsurface structure, such as the number of preferential flow pathways (e.g., fractures) that are available for fluid and heat transport. We present a combination of simple analytical models that maximize the profits of an idealized synthetic geothermal reservoir, while considering reservoir structural uncertainty, using expected net present value. For a typical case, we find that effective reservoir transmissivity and inter-well spacing exert the largest controls on the lifetime profitability of an idealized geothermal reservoir, and for a given reservoir there exists a critical number of hydraulically active fractures beyond which additional fractures provide no increase in lifetime profits. Given initial reservoir characterization data, our model simulates reservoir performance that predicts financial outcomes, which operators can use during initial exploration stage. These predictions are also useful during normal operations to consider strategies, such as drilling make-up wells, to mitigate the effects of production-induced thermal drawdown.

中文翻译：

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不确定性下裂缝性岩石储层的地热生产优化

摘要 地热能资源在世界范围内是高度可用但未充分利用的资源。以前的研究试图了解储层对地热生产的响应并优化生产率以最大限度地提高地热储层的生命周期利润；然而，这些研究在很大程度上忽略了地下结构的不确定性，例如可用于流体和热传输的优先流动路径（例如，裂缝）的数量。我们提出了一个简单分析模型的组合，这些模型可以最大化理想化合成地热储层的利润，同时使用预期净现值考虑储层结构的不确定性。对于典型案例，我们发现，有效的储层导水率和井间间距对理想化地热储层的寿命盈利能力施加了最大的控制，并且对于给定的储层，存在一定数量的水力活动裂缝，超过该数量的额外裂缝不会增加寿命利润。给定初始油藏特征数据，我们的模型模拟油藏性能，预测财务结果，运营商可以在初始勘探阶段使用。这些预测在正常操作期间也很有用，可以考虑诸如钻补井之类的策略，以减轻生产引起的热压降的影响。对于给定的储层，存在一定数量的水力活动裂缝，超过这个数量，额外的裂缝不会增加寿命利润。给定初始油藏特征数据，我们的模型模拟油藏性能，预测财务结果，运营商可以在初始勘探阶段使用。这些预测在正常操作期间也很有用，可以考虑诸如钻补井之类的策略，以减轻生产引起的热压降的影响。对于给定的储层，存在一定数量的水力活动裂缝，超过这个数量，额外的裂缝不会增加寿命利润。给定初始油藏特征数据，我们的模型模拟油藏性能，预测财务结果，运营商可以在初始勘探阶段使用。这些预测在正常操作期间也很有用，可以考虑诸如钻补井之类的策略，以减轻生产引起的热压降的影响。