Study on dispersion property of a novel profile control agent Yamei Guo EOR Research Center, China University of Petroleum, Beijing

Outline  Background  Purpose  Methods  Results  Conclusions

 Background—studies of LPS 1. Definition: Linked polymer solution (LPS) is a dispersion which is made up of linked polymer coils (LPC) linked by aluminum ions in water. 2. Properties: SEM photograph of LPC The size of LPC is about hundreds nanometers Thermodynamic stable Good injecting, deformable and plugging property

3. Problems of LPS High temperature Prepared with treated water Oxidation degradation of HPAM over 70ºC LPC is not formed To seek a new profile control agent could be prepared with treated water and used in the reservoirs at over 70ºC

 Purpose 1.Properties of the new profile control agent could have Good dispersion stability High temperature tolerance (≥70ºC) High salinity tolerance (≥50 g∙L -1 )

2.Basic properties of sulfomethylated phenol formaldehyde resins—SMP 1. The molecular structure of SMP is consist of benzene rings which are unable to be degraded at high temperature. temperature tolerance (≤180 ºC ) 2. The molecule of SMP has -CH 2 SO 3 Na group, more water soluble. Salinity tolerance (≤150 g∙L -1 NaCl)

 Phenolic rings are linked via methylenes at ortho-para positions.  Sulfomethylations are mostly linked to premier phenolic rings at double ortho positions. 3.Molecular structure of SMP

 Methods To study dispersion properties of SMP in water by Coagulation value Turbidity Hydrodynamic diameter Zeta potential

 Results of this study 1.D h and zeta potential of molecular aggregates in distilled water Concentrati on of SMP / g∙L -1 D h / nm Zeta potential / mV D h and zeta potential of SMP (pH=8.2 ， 25ºC) Hydrodynamic diameter at 0.01g∙L -1 of SMP (25ºC) The dispersion of SMP in water is a lyophilic colloid

ElectrolyteConcentration of electrolyte / mol∙L -1 Coagulation valueRatio of coagulation value mol∙L -1 g∙L -1 NaCl CaCl MgCl AlCl × × ×10 -4 Na 2 SO Coagulation value of SMP solution (25 ºC )  The stability of SMP solution is influenced by the positive ions

3. Effect of NaCl on the stability of SMP solution 1) NaCl, zeta potential, D h, NTU, the stability of solution 2) The range of D h is 100 nm ~500 nm when concentration of NaCl is less than 150 g·L -1 The effects of concentrations of NaCl on The stability of SMP solution (pH=8.2 ， 25ºC)

4. Effect of pH on the stability of SMP solution At pH<3.0, positive charged, pH, H +, zeta potential, D h ; At pH >3.0, negative charged, pH, OH -, zeta potential, D h ; At pH=3.0, D h is the biggest and the absolute value of zeta potential is the least in the solution; At pH=0~12, the turbidity values of solution are small, the solution is stable. Effects of pH on the stability of SMP solution (25ºC)

PropertiesLPSSMP Size of dispersed particles20nm~2000nm100nm~500nm DeformationWellwell StabilityWell PreparationCross linking in fieldsSynthesis in factories Salinity tolerance≤ 50 g∙L -1 ≤ 150 g∙L -1 Temperature tolerance≤ 70ºC≥ 95ºC pH5~83~12 5. Comparison between LPS and SMP solution

 Conclusion 1.The hydrodynamic diameter of the SMP molecular aggregates is about 100 nm and the molecular aggregates are negative charged in distilled water. 2. The ratio of critical coagulating concentration (CCC) of NaCl to CaCl 2, MgCl 2, AlCl 3, Na 2 SO 4 for the SMP solution is 1:0.032:0.66: : Hydrodynamic diameters of molecular aggregates and turbidity of the SMP solution increase and absolute values of zeta potential of the molecular aggregates decrease with increasing concentrations of NaCl. 4. At pH=0~12, the turbidity values of solution are small, the solution is stable.