On Salt Tolerance Of Heat-resistant Foam Drilling And Oil Extraction Mechanism And Application

This thesis is divided into two parts:In the first part, we mainly do research on the formula of temperature and saltresistant selective foam for water plugging, and also do performance evaluation.Foam is unstable under the conditions of high temperature and salt in the stratum,which is why the foam plugging agent well laboratory evaluated cannot besuccessfully used in the field.We have done research of salt-tolerant stable foam from2008,and now we have made some achievements.In this paper,we mainly evaluatesalt resistant stability,temperature resistant stability and oil resistant stability of thefoam,and also study the mechanism of them.The stability issue of foam need to be overcome before the foam is applied to theoil field. The foam system will not survive in the stratum, unless it is salt resistant andtemperature resistant. So we choose DM5512as the main foaming agent. SurfactantDM5512is salt resistant and temperature resistant. Its structure has some groups, suchas double bond,-SO3H, polysilicon and oxygen structures. The charge density and theability of hydration of sulfo group is large,so the cationic attack is insensitive, and itcan also have chelation on metalion together with double bond. Therefore surfactantDM5512has a strong anti-electrolyte capacity, and the temperature resistance ofpolysilicon and oxygen structure is good. There are also betaine and tea saponin,which are mixed with DM5512into OP-1,so that OP-1has good salt tolerance andfoaming properties.In order to increase the stability of the foam system, foam stabilizer is needed.Such as PAC, HPAC, XC, A1. Finally we choose the foaming stabilizer WD-1withtemperature resistance and salt-tolerance through mixing several stabilizer. In order toincrease the stability of the foam, a stabilizer must also be added into the formulary,such as PAC, HPMC, XC, A1.The bubble plugging agent in this thesis is a kind of selective plugging agent, itsbest characteristic is blocking water but oil. Regardless of water flooding or steam flooding oil exists underground all the time. So the foam system we made must havegood oil resistance.Experiment proves that the foam system has a good stability inthe case of6%of the diesel adding.The foam system is always unstable underground because of many externalinfluencing factors.We evaluate the salt tolerance, heat resistance,oil resistance andwater dilution ability, finding that the selective bubble plugging agent formula’s salttolerance reaches1×106mg.L-1, heat tolerance reaches130℃, oil pollutionreaches6%. So this foam system is adapt to oilfield water plugging.In the second part, we make bench test to compare the rare earth diesel fuel-savingadditive with the other two kind of surfactant fuel-saving additives, and also analysisthe fuel-saving mechanism. We started this subject from2006.Nowadays, China road transport’s fuel consumption increases year and year. PM2.5is becoming seriously, so improving the fuel’s Utilization has been a problem thatcann’t be ignored.There are many fuel-saving methods all over the world, among ofall the chemical fuel-saving is the most important method by adding fuel-savingadditives to reduce fuel consumption, while no adverse effect to the other useperformance.In this part, it introduces nano-rare earth active catalyst NAC-26which is madeof rare earth ligand compound,surfactant,cosurfactant,stabilizers and solvents.What’more, we make bench test to compare the rare earth diesel fuel-saving additivewith the other two kind of surfactant fuel-saving additives, Experiment proves thatNAC-26can greatly improve diesel fuel-saving efficiency, as well as greatly reducethe content of trace metals in the oil, so it is a very good fuel-saving additive.