Application And Research Of Latex Cement Slurry System

High molecule polymer materials as oil well cement additives are applied widely in cementing job of oil field which plays a important role in improving cementing quality. This paper describes field application and research of polymer latex cement slurry system, which contains polyvinyl alcohol, a water soluble polymer as main component.This paper details the relations between cementing job, oil well cement additives and concepts concerned, summarizes the forefathers achievements, analogizes Vernon methods, designs the polymer slurry system and special test instruments.The main researching content is the behaviors of polyvinyl alcohol as oil well cement additives and matching components affect to performances of polymer slurry system.One of the basic researching principles is the polyvinyl alcohol cross link with borax under alkaline condition, the basic aim is to control fluid loss by film form in cross linking.The polyvinyl alcohol and borax don't cross link under the acid condition, but they do under the alkaline condition. The organic acid is used to control acidity of slurry mixed and prevent cross linking before mixing with cement. When cement medium exists, the polyvinyl alcohol and borax crosslink to form the netted texture, some organic acid are supposed to participate the cross linking to form flexible stereo scope netted texture. This structure adsorbs to cement grains, preventing free water migration in slurry. The absorbability makes slurry system form low permeable elastic film on the filtration interface under the condition of measure difference, the film is used to control fluid loss to the formation, reduce shrink age of cement, prevent fluid migration , keep normal setting of slurry in the hole . In addition, the polyvinyl alcohol matches with other components to make the slurry system have features such as "right angle thickening", "zero free water" and "shear dilute" and so on.This paper summarizes the results of field test and application, analyzes the specific problems in polymer slurry system, plus forwards the future research ideas.The research works enrich and develop the migration prevention theory in cementing job , reach a new level in developing cement additives . During field test and application, the research works play a important role in solving high pressure zone cementing and horizontal well cement in Daqing of Geological mineral department and offshore deep gas zone cementing in Bohai oil field.