experimental investigation of physical and chemical properties of drilling foam and increasing its stability

this investigation presents the effect of various parameters on foam stability and its rheological properties. the underlying idea of this experiment is generating of drilling foam with uniform bubbles. the main problem of foam using is controlling its stability during field application. the most important parameters which cause instability in foam are gravity drainage, gas diffusion and bubble coalescence. among these parameters gravity drainage has the highest effect on foam instability in field application. for measuring of drainage effect it is necessary to produce foam with uniform bubbles. this experiment was performed with a specific foaming system which constructed in research institute of petroleum industry (ripi) just for this point. this foam system consisted of an apparatus which injected nitrogen gas through a porous plate into the foam solution.in each test one parameter was variable and the effect of this variation was measured on foam properties. the main parameters which investigated in this experiment were temperature, foamer concentration, ph effect, stabilizers, and contaminants. obtained results from testing of each parameter can be used simultaneously to improve the foam stability in elevated temperature. in this way by changing of physical and chemical properties of foam, it becomes more stable in real condition of wellbore.