Supercritical CO₂ fracturing can form a more complex fracture network in rocks than hydraulic fracturing and avoid aqueous phase trapping damage in reservoirs. Thus, it is a promising alternative to hydraulic fracturing for enhancing the production of low-permeability hydrocarbon reservoirs. In this study, a new numerical model for predicting the wellbore temperature and pressure during supercritical CO₂ fracturing was established based on thermodynamics, heat transfer, fluid mechanics, and a numerical solution method. In the new model, the physical properties of CO₂ are calculated with the Span–Wagner and Vesovic models, and the heat generated by fluid friction losses is absorbed by the tubing and CO₂ according to the contact coefficient. The model was used to examine the influences of the injection rate and temperature on the wellbore pressure and temperature. The results indicated that both the heat transfer and pressure in the wellbore are transient processes in the initial stage of injection; as the injection time increases, the heat transfer and pressure in the wellbore can be considered steady processes. The CO₂ temperature in the wellbore is considerably affected by both the injection temperature and rate, whereas the wellbore pressure is greatly affected by the injection rate but weakly affected by the injection temperature. The CO₂ pressure in the wellbore decreases rapidly as the well depth increases because of high fluid frictional resistance, so a drag reducer suitable for liquid CO₂ needs to be developed.

与水力压裂相比，超临界CO ₂压裂可在岩石中形成更复杂的压裂网络，并避免水相捕集对储层的破坏。因此，它是水力压裂的一个有前途的替代方法，可以提高低渗透性油气藏的产量。在这项研究中，基于热力学，传热，流体力学和数值求解方法，建立了一个新的数值模型，用于预测超临界CO ₂压裂过程中的井眼温度和压力。在新模型中，使用Span–Wagner和Vesovic模型计算了CO ₂的物理性质，而流体摩擦损失所产生的热量则被油管和CO ₂吸收了。根据接触系数。该模型用于检查注入速率和温度对井眼压力和温度的影响。结果表明，井筒内的传热和压力在注入初期都是瞬态过程。随着注入时间的增加，井眼中的传热和压力可以被认为是稳定的过程。井眼中的CO ₂温度受注入温度和注入速率的影响很大，而井眼压力受注入速率的影响很大，但受注入温度的影响较小。一氧化碳₂由于高的流体摩擦阻力，井眼中的压力随着井深的增加而迅速减小，因此需要开发适用于液态CO ₂的减阻剂。