Optimization Of Inorganic Geopolymer Gel Formulation And Evaluation Of Plugging Effectiveness

With the extension of development time,The development of large pore and extra high permeability zones in some reservoirs in Bohai oilfield is more and more serious,therefore,it is worth researching and discussing that identifying the large pore and super high permeability strip and optimizing the plugging agent with high plugging strength,low drug cost and strong adaptability in the offshore oil field.Aimed at the physical properties and fluid properties of a reservoir in Bohai,experimental study on identification of large pore and optimization of inorganic composite geopolymer gel,formulation optimization and injection process optimization were carried out,guided by physical chemistry,polymer materials and reservoir engineering,taking chemical analysis,physical simulation and instrument testing as the technical means.The advantage level of large pore of D2 well,D7 well and D12 well in the second small layer of the east two section of SZ36-1 Oilfield is two distinguished by a double logarithm method for water and oil ratio,the advantage level of large pore of the other wells is three,we use the pipe flow model to calculate that in the control range of D2 well in the second small layer of the east two section of S Oilfield,the volume of large pore is 346.7×10~4m~3,the average permeability is 15.2?m~2,the average radius of the channel is 25.5?m.Core experiment shows that the contribution of hole(depth and aperture)to core average permeability is not high,it means that even there are high strength and large channels or extra high permeability zones in the vicinity of injection production wells during the process of reservoir development,but the growth of reservoir average permeability is not obvious,it is easy to cause us to misjudge.The curing agent is recommended as"NaOH",tackifier as the"inorganic tackifier"and retarder as the"compound retarder."The formula was selected as"tackifier 5.0%+curing agent 0.1%+retarder 0.25%+main agent 30%".Under this formula,the curing time is about90h,The influence of retarder on the curing time is the most obvious.With the concentration of retarder increasing,the curing time is prolonged,and the curing time ranges from 5.5h to480h.The plugging agent is not sensitive to water,besides,it has the characteristics of good alkali resistance,but poor acid resistance.Compared with hydrochloric acid and hydrofluoric acid,the effect of soil acid on this kind of plugging agent is better,and the dissolution time is about 4 hours.The plugging agent has the compressive strength of about 1MPa,in addition,the permeability is quite low,and the plugging effect is good.Practice shows that if inorganic geopolymer gel predominant channel plugging technology and chemical flooding technology are combined,we can get the double effect of"blocking+flooding",so that the effect of oil increasing and precipitation is more obvious;Oil displacing agent and water returning from low permeable layer and the matrix layer of the high permeable layer into large pore are delayed with the increase of plugging distance,their wave area increases so that recovery rate increase...