Experimental Research On Foam Stability & Foam Breaking Methods

Foam drilling technique is one of Underbalanced drilling types. Foam drilling overcomes on the disadvantages of drilling with high density fluid drilling, as well solve the problems associated with air and mist drilling.Foam drilling has been widely used in the field of mineral, hydrology and oil. Although the wide using of foam drilling, fundamentals of this technique still unknown.One problem of foam drilling is during drilling operations is foam used only once and can not reused again this led to high cost and limit of using foam drilling, also the large volume generated from foam during drilling is another problem to the environment.Foam breaking is one of the main problems of this research, and by solve this problem foam drilling technique will develop and the using of this technique will be in raise in China. Foam is an aggregate of bubbles surrounded by thin liquid films. Foam is unstable, and to asses the characteristics of foam, foam stability should carefully study.Foam stability is the most important parameter to study foam and it is mean the foam time last, and often we use the foam half life to evaluate foam stability. Foam stability depends on the speed and slows of the bubbles. Over the period of time, in China and in over the world several researches have been introduced stability and different assumptions have been presented.During this period of research various methods have been developed to evaluate foam stability as follows:1. Foam stability evaluation of one dimension.2. Foam stability evaluation of tow dimensions.3. Foam stability evaluation of three dimensions.The parameters effect on stability:1. Molecular composition of active materials.2. Concentration3. Relation of the molecular4. Foam agent type5. Bubbles viscosity6. Surface elasticity7. Electric ability8. Solid grain size9. Oil concentration10. pH11. Pressure12. Area mineralization and type13. TemperatureLaboratory results led to that the diameter of the discs using during foam breaking should not be large and the suitable diameter from the results was 0.6mm. The high the Pressure, the high the foam breaking, except at very high pressure led to high speed of foam flows and decreasing in foam breaking.The length of pipes we used during the experiments is various.