Conceptual design and development of a non-invasive drilling, well completion and well stimulation fluids

油气井在钻井、完井、增产等作业过程中，由于地层损害，产能显著下降。威尔斯井的生产能力受到复杂的岩石/流体相互作用的损害。在大多数情况下，定期关闭受损的威尔斯井进行清洗。纠正损害会导致延迟，并可能需要昂贵的油井增产作业。 将研究两种新的非侵入性流体概念在油气威尔斯井中的适用性：采用微泡作为桥接机制的流体;以及在流过多孔介质时产生高摩擦压力损失而在井中流动时不产生过多损失的流体。微泡具有在储层的孔隙中形成阻止流体侵入的桥的独特能力。通常，桥接机制通过“贾明效应”来解释，该效应描述了一种非润湿流体将润湿流体推入毛细空间所需的压力。 由于微泡结构和性质的复杂性，尚不清楚这种效应究竟在什么条件下发生。因此，本论文将从实验和理论两方面研究微气泡的架桥机理，以及微气泡对流体过滤速率的控制效果。在粘弹性流体通过多孔介质的流动期间观察到的压降是流体剪切和拉伸粘度的强函数。对于粘弹性流体，拉伸粘度可以比剪切粘度大几个数量级。这将导致压力损失的巨大增加，这通常归因于内部蛋糕的建立。将进行实验和理论研究，以研究拉伸粘度对流体过滤速率的影响。如果能够有效地最大限度地减少与钻井、完井和增产作业相关的生产力损害，则可能会实现显着的储量增加。非侵入性流体技术是解锁额外资源的关键之一。未能充分利用这些新技术将导致错失机会，并使潜在的有价值的碳氢化合物矿床“在经济上陷入困境”。"

Productivity of oil and gas well decreases significantly due to formation damage that occur during drilling, well completion, and well stimulation operations. The productive capacity of wells is impaired by complex rock/fluid interactions. In most cases, the damaged wells are shut down periodically for cleaning. Rectifying the damage causes delays and may require expensive well stimulation operations.  Two new non-invasive fluid concepts will be investigated for their applicability in oil and gas wells: fluids employing microbubbles as bridging mechanisms; and fluids which generate high friction pressure losses when flowing through porous media without generating excessive losses while flowing in the well. Microbubbles have the unique ability to form a bridge in the pores of the reservoirs which stops fluid invasion. Commonly, the bridging mechanism is explained through the "Jamin Effect" which describes the pressure needed for one non-wetting fluid to push a wetting fluid into a capillary space.  Due to the complexity of the microbubble structure and nature, it is unknown under exactly what conditions this effect takes place. Therefore, experimental and theoretical studies will be conducted to investigate the mechanisms of bridging, and the efficiency of controlling fluid filtration rate by using microbubbles. The pressure drop observed during the flow of viscoelastic fluids through porous media is a strong function of the fluid shear and extensional viscosity. For viscoelastic fluids the extensional viscosity may be several orders of magnitude larger than the shear viscosity. This will lead to a tremendous increase in pressure loss, which is very often attributed to the building of internal cake. Experimental and theoretical studies will be conducted to investigate the effect of extensional viscosity on the fluid filtration rate. Significant reserve additions may be realized if the productivity impairment associated with drilling, well completion, and stimulation operations can be effectively minimized. Non-invasive fluid technologies are one of the keys to unlocking additional resources. Failure to fully exploit these new technologies will result in missed opportunities and leave potentially valuable deposits of hydrocarbons "economically stranded."