Identifier

etd-11142013-173050

Degree

Doctor of Philosophy (PhD)

Department

Petroleum Engineering

Document Type

Dissertation

Abstract

The use of foams can be found abundantly in many applications in a wide range of industries, including oil and gas industry. Although understanding foam flow behavior is crucial for the optimization of such applications, the complex flow behavior of foams has been a major challenge. Recent experimental studies with surfactant foams presented a new way to characterize foam flow characteristics by using two flow regimes: the low-quality regime showing either plug-flow or segregated-flow pattern, and the high-quality regime showing slug-flow pattern. This study consists of three main components: (1) experimental investigation of foam rheology in pipes; (2) building up of a new foam model consistent with lab-measured experimental data; and (3) use of the model in petroleum drilling hydraulics modeling and simulation. The major outcome of this study can be summarized as follows. First (Part 1), by conducting foam flow experiments in pipes, this study shows the concept of two foam-flow regimes is still valid and effective not only with surfactant foams but also with foams in the presence of additives such as polymers and oils. This finding is important because many field applications of foam flow involve some levels of additives. Second (Part 2), this study for the first time presents how to build a foam model which is consistent with two foam-flow regimes evidenced by experimental data. The model requires four model parameters – two parameters to capture rheological properties (e.g. consistency index and flow behavior index, if power-law rheology is applied) and two parameters to define the dependence of foam rheology to gas and liquid flow rates in both foam flow regimes. Third and last (Part 3), the significance of this model is verified by implementing it into existing foam drilling hydraulics calculations in a 10,000 ft vertical well in which foams are injected down into the drill pipe, through the drill bit and circulated up to the surface along the annulus. The results show that this new foam model equipped with two flow regimes is advantageous over the conventional foam model especially when foams become dry and unstable in the well, improving the accuracy.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Kam, Seung

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