Modification of Green Polymer for High Temperature and Salinity Carbonate Reservoir

A large amount of oil remains unrecovered in most oilfields as this oil is trapped in the fine pore structure of the rock. Engineers and scientists are constantly engaged in developing more effective methods for recovering this oil as the discovery of new oilfields with large reserves is getting rarer. The technology developed from this endeavor is known as enhanced oil recovery (EOR). Oil production from EOR methods continues to supply an increasing percentage of the world's oil. The petroleum industry has engaged in research and development of various EOR processes needed to produce the oil left behind by conventional methods for more than four decades. Polymer flooding an efficient chemical enhanced oil recovery method and its success is depended on the type of polymer used, design criteria adopted, and the ability to find the optimum operating conditions. Furthermore, most polymers used in EOR are synthetic and not environmentally friendly. Thus, recently the use of biodegradable polymers gained attention in EOR. Three biopolymers have good EOR properties. These are Xanthan Gum, Sclerogucan, and Schizophyllan. Among these biodegradable polymers, xanthan gum (XG) is the cheapest green polymer. It is a water-soluble polymer and widely used in EOR processes. However, its effectiveness is limited in high-salinity and moderate high-temperature oil reservoirs because of its poor salt tolerance and low viscosity at moderately high temperatures. Both Academia and Industry are trying to develop XG to work at high salt concentrations at high temperatures. Unfortunately, such type of XG is still unavailable. To improve the salt tolerance at high temperatures, XG can be modified by inserting functional groups which increase tolerance of concentrated salt conditions. The direct impact of such modifications should improve the effectiveness of XG in enhanced oil recovery as high temperature and salinity are common in the Kingdom. The proposed modification will improve salt tolerance even at moderate and high temperatures. In particular, the role of specific ions in the brine will be investigated for its impact on the stability and efficiency of these polymers. This study will also evaluate properties and factors such as polymers retention, inaccessible PV, permeability reduction, polymer mobility, the effect of salinity and temperature, and cost. In addition, these properties and cost factors are compared to those of HPAM (Hydrolysed Polyacrylamide), used as a benchmark. The study will also consider developing screening criteria for biodegradable polymers. The outcomes of the proposed research include the following: i. Formulation for EOR of the Kingdom oil fields. ii. A set of performance criteria for EOR applications. iii. New facilities for the characterization of polymers for EOR applications. iv. Training of graduate and undergraduate students. v. Journal publication(s) and/or patents on the new formulations that will be developed.