Hydrophobically Associating Polymer Indoor Research And Field Applications

Compared with Polyacrylamide(PAM) used extensively in oil field , Hydrophobic Associating Polymer Solution(HAPS) has some special characteristics such as viscosity increased effectively , anti-temperature , salinity tolerance , shear resistance and shear recovery, which make it have a wide application prospect in EOR area and could substitute for HPAM to be oil displacement agent and profile modification agent for high temperature and salinity reservoirs.Based on much documents on HAPS, indoor research and pilot tests of HAPS had been carried out under the condition of high salinity and high temperature reservoirs, so as to make sure whether HAPS can increase viscosity effectively, can resist temperature and salinity, can resist shear and can resume the viscosity of bulk solution, which were to be expected to solve the instability problem of PAM under the condition of high salinity and high temperature reservoirs, to solve the problem of lacking of fresh water resources while polymer displacing or compound chemical displacing. So the research implemented can not only has theoretical significance, but also has realistic one.The indoor research and pilot test results of HAPS under the condition of high salinity, high porosity and permeability reservoir in Bo-hai oil field indicated that the dissolving capacity of HAPS can satisfy the requirement on offshore, and HAPS has the ideal performance such as increasing viscosity, resisting shear, stabling for long-term and controlling mobility well and reducing permeability of reservoir under reservoir condition .At the same time, super-molecular aggregates and network structure formed by HAPS were proved , thus can benefit HAPS to increase viscosity , and to solve the problem of lacking of fresh water resources on offshore.Temperature and salinity tolerance profile modification and plugging was developed by using the physical association characteristics between inter-molecules of HAP molecule and adding cross linker to HAPS solution, which combines the virtues of physical aassociation and chemical crosslinking to form three-dimensional reticular structure. This system has moderate crosslinking time, good stability, good temperature and salinity tolerance, good shear resistance, excellent ability to modify profile. On the other hand, this system has can ameliorate profile. By which, the volume of polymer and crosslinker can be saved a lot .At last, the crosslinking mechanism of the profile modification system on HAP was analyzed, too.Under the condition of high salinity (17×10~4mg/L ) and high temperature (more than 95 degrees Centigrade ) reservoirs, the HAPS has good stability. The HAPS can exhibit shearthinning performance before injection. After injection, the HAPS can keep its high viscosity and the crosslinking can be formed in depth , too, which makes it modify profile in the deep reservoir.Pilot results of HAPS profile modification system shows that HAPS can remain its stability for long-term under the condition of high salimty and high temperature reservoir, which indicated that HAPS has good temperature and salinity tolerance, shear resistance and shear recovery , high efficiency to increase viscosity and excellent ability to modify profile, and also indicated that HAPS can solve the instability problem of conventional polymer profile modification system under the condition of high salinity and high temperature reservoir.From the effects of pilot tests, HAPS exhibited good temperature and salinity tolerance and shear resistance performance whether employing it as polymer displacing agent or as profile modification system. And good results have been obtained whether under high salinity and high temperature reservoir or under high porosity and permeability reservoirs, thus widening HAPS's application scope in EOR area.