New methodology for foam cement mixing to better reflect onsite mixing method

Abstract

Foamed cement has become a well established cementing method for many applications in oilwell cementing all over the world. A key factor to a successful foam cement job is an optimized cement slurry design. To achieve optimal slurry design the project engineer is working in close collaboration with the onshore cement laboratory. In laboratory testing, the foam stability is an important factor. In recent years it is claimed that the foam stability results from the cement laboratory seems not to fully match with the actual results in the field. The experience is that slurries seem to be somewhat more stable in the field than in the laboratory. Today, laboratory foam cement is created in a closed blender according to ISO 10426. The main focus in this thesis is to investigate a new way of creating foam cement in the laboratory approaching a replicated, downscaled model of the method that is used in the field. An open, atmospheric flow loop was designed and built with a tee shaped construction joint for nitrogen injection to resemble onsite foam generation. The results showed that the foam generator loop was able to create foam, but the bubble size was significantly larger compared to the laboratory closed blender foaming process. Hence a good deal of improvement of the prototype is required.