The Research Of Bridge Eccentric Integrated Water Injection Technique

Daqing Oilfield has entered into the high water cut period at present. There are higher demands to water injection technologies in order to keep the stable oil production. The water injection techniques in the Daqing Oilfield mainly include three categories: the conventional eccentric water injection technique, the bridge eccentric water injection technique and the concentric integrated water injection technique. The conventional eccentric water injection technique is gradually replacing by the bridge eccentric water injection technique that is suitable for multiple separate layer water injection. However, it is hard to isolate some laminae with thin barriers with the bridge eccentric l injection tools, for their length is too long (normally over 8m). While, two to four thinner zones can be controlled independently with the concentric integrated water injection technique. Nevertheless, the size of its blanking plug is too big to easy forming scales when water quality is poor, which will lead to difficult fishing operation. In light of this situation, it is necessary to combine the advantages of two techniques together to develop a novel injection technique: bridge eccentric integrated water injection technique.The main packer and the injection mandrel are integrated together into one piece based on the original bridge eccentric water injection. The integrated packer has dual functions of both isolating formations and the injection mandrel of regulator. Two nozzles are set into one integrated packer that controls the two adjacent zones'water injection rates. At the same time, there is no limit on the numbers of injection intervals because the injection tools are eccentric This allows different layers to be subjected to different flow rates, or the individual zones can be pressure tested independently, instead of in a co-mingled condition. The data thus collected from a single zone is free of the complications associated with trying to interpret a set of two or more zones that are subjected to simultaneous injection or pressure testing. Clearly, this allows for far more precise field management.The widespread hydromechanics software, FLUENT CFD was adopted to numerically simulate different parameters of the eccentric integrated blanking plug, and to analyze their relations to each other and finally to provide the basis for optimal structures and sizes.From the above description in this paper, the bridge eccentric integrated water injection technique was developed directly aiming at solving the new problems aroused in the oilfield. It will definitely have good applications and prospects in the future.