The Displacement Characteristic Research And Application Of Ultra High Molecular Weight HAWP

Polymer flooding is one of the main ways to enhance oil recovery considerably in our country. It has been widely applied in Da qing and Sheng li oil field and the technique is more and more mature. The research and application level of polymer flooding in our country is in global leading position. But with the deep research and large scale application to polymer flooding, the quality resources, low temperature and salinity reservoir, have been widely developed and there is nothing more such resources. So the facing main target of polymer flooding is high temperature and high salinity reservoir, the reservoir temperature is above 80 ℃ and the formation water salinity is above 20000mg/L, the conventional polymer HPAM used in oil field at present can’t meet the viscosifying, temperature tolerance and salt-resistance requirement, it can not be applied in high temperature and high salinity reservoir, the new type polymer with well temperature tolerance and salt-resistance performance is in large demand. HAWP is one of the research fields for polymer with temperature tolerance and salt-resistance performance. At present it has made some progress. Through enhancing HAWP molecular weight and introducing temperature and salt resistance monomer the synthetised ultra high molecular weight HAWP AP-P5 has realized industrialization production and it can possibly settle the EOR technical problem in high temperature and high salinity reservoir.According to high temperature(80℃)and high salinity(20000mg/L)reservoir conditions, ultra high molecular weight HAWP AP-P5 is studied in this paper with an emphasis on its molecular structure, solution, oil displacement characteristic and application performance. By the way of infrared spectrum, NMR, AFM, dynamic light scattering and rheology, the molecular structure characteristic, rheological behavior, long term thermal stability of AP-P5 are studied and compared with the conventional polymer. It proves that there is no obvious critical associating concentration for AP-P5. At the same time the ultra high molecular weight HAWP is qualified with relative high molecular weight, superior temperature and salinity resistance performance, long term thermal stability. Through physical simulation experiment in house, it is studied of the molecular structure, polymer loading, permeability, permeability ratio and other parameters on oil displacement effect, it is recognized of the macro displacement characteristic of ultra high molecular weight HAWP under high temperature and high salinity reservoir conditions. With the help of CT technology, the micro sweep character, oil displacement rule analysis and quantitative statistics of ultra high molecular weight HAWP and its binary combination flooding system are studied. Based on comparison of micro responsed remaining oil it is studied of polymer flooding and binary combination flooding enhancing oil recovery capability, it proves that the ultra high molecular weight HAWP is qualified with the ability of expanding sweep and improving micro displacement capacity. With the IFT relaxation method, through multi exponential fitting of the perturbed interface tension decay curve, dilatational rheological parameters with different frequency are calculated and interfacial behavior of HAWP are discussed. It proves that "ultra high molecular weight HAWP", the interraction of "ultra high molecular weight HAWP"and surfactant take some effect on interfacial film. Its high interfacial elastica and viscosity is favor of triggering residual oil. The mathematical model of degree of hydrolysis, viscosity and borehole shearing are built and improved, which realized numerical simulation function of ultra high molecular weight HAWP. In the end pilot project is scheduled and implemented. The result of individual well injection shows that injection pressure rises obviously, the field operation is normal, the precipitation and oil increment are observed initially in the center well. It has a preliminary confirmation in three class high temperature and high salinity reservoir in Sheng li oil field and shows a good application prospect.