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

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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."