The Synthesizing Technique Of Clay Stabilizers

The studying period on clay stabilizers can be divided into three stages that from the 50s to the late 60s the inorganic salts are mainly used to stabilize clay.in the 70s are inorganic multinuclear polymers and cationic surfactants ,and after the 80s the studying and experiments on cationic organic polymers stabilizing clay are mainly carried out.Apllication of clay stabilizers as a technical measure to protect oil bearing formation started from the early 90s in daqing oil field, but generalized in the late 90s.The actions of clay stabilizer protecting oil bearing formation are preventing clay mineral from hydrating swelling and scattering migration which will block flowing porous canal , lead to permeability declining and influence the effictiveness of oilfield exploitation.In this article we take the synthesizing technique of clay stabilizer as a research object and start from analysis of clay electrical property , water-sensitiveness reasons of storage formations and relations between clay mineral types and water-sensitiveness.The emphasis is on the synthesis and preparation of the clay stabilizer made from epoxy chloropropane .By laboratory experiments we have found the optimum polymerization reaction time, temperature, amount of initiator and monomer molar ratio in the synthesis of PTA clay stabilizer.The clay stabilizer laboratory performance evaluation experiments indicate that PTA has favorable ability of prohibiting clay hydrating swelling and is an ideal long-effictive clay stabilizer.The PTA has been applied on the job site on the basis of laboratory application experiments of crude core.By the late 2002, the fifth oil recovery factory of Daqing oil field had treated 680 wells via applying PTA to protect oil-bearing formations and raised productive capability of new well effectively.enhanced the usage degree of storage formation,improved the exploitative effect of oil field and gained great economic effect. On the basis of application of synthesizing technological studying of clay stabilizers we have acquired five conclusions, i.e.:1 , The cationic clay stabilizer(PTA) is made from epoxy chloropropane and dimethylamine. Its optimum reaction time is 5h,temperture is 65 ,amount of initiator is 1.0% and molar ratio of unit volume is 1.5:1.2, The PTA has favorably protective behavior for the core of Xingnan Daqing.The recovery ratio of debris is greater than 95%,the expansion ratio of clay is less than 3%,the harm ratio to core permeability is less than 10% and it has good persistence comparing with KCI and NH4CI.3, The PTA may be by means of actions of its surficial positive charges and intermolecular forces among macromolecules to absorb on the surface of clay grains to prevent clay from hydrating swelling.4, The practical application experiments indicate the PTA perforating fluid can improve producing fluid intensity of oil well 0.9t/d.m, enhance injecting water intensity of injecting water well 3.31 nrvVd.m.After adopting protecting oil-bearing formation measures.the skin coefficient of oil well decreased 0.22 and the perfect extent of oil well has been well improved.5. The effictiveness of multiple protecting agents is much better than clay protecting fluid alone .The ratios of whole well sandstone and sucking water depth have improved 18.4 and 4.5 seperately.