The Bubble Breaker

Erik Schrama Richard Fernandes Shell International Exploration and Production B.V.

Abstract

The bubble breaker is an orifice plate that can be installed in a gas lifted or naturally producing well with associated gas to enhance production. By generating intense liquid turbulence the bubble breaker breaks up large bubbles and gas slugs into bubbles smaller than 1 mm. The small bubbles move slower through the liquid and are distributed more homogeneously over the cross section of the production tubing. As a result the small bubbles reduce the hydrostatic head in the well. To generate the turbulence and the small bubbles only a small pressure loss over the bubble breaker is required. If the well is deep enough and the gas-to-liquid ratio is within certain boundaries this results in a net reduction in flowing bottom hole pressure and an increase in production.

The bubble breaker project started as a co-called Game Changer project. At Shell EP Technology in Rijswijk, The Netherlands, different bubble breakers were tested in an 18-meter high, 72 mm diameter Perspex test facility. The proof-of-concept experiments showed that it is indeed possible to break up bubbles and that they can reduce the hydrostatic head significantly.

A field trial in Central Africa showed that the bubble breaker works. A production increase of some 10% could be seen and the flowing gradient survey showed a change in gradient.