Study on the Application of Whole Process Monitoring and Control Technology for Separated Layer Water Injection to Block

摘要

Abstract Oilfield development in China has entered the high water cut stage. Waterflooding development is faced with ineffective water injection and rapid increase of water cut, due to complex injection-production relationship, unbalanced production and severe interlayer contradictions. Besides, total number of separated layer injectors increases with years, single-well layers subdivision becomes more elaborate, and the measuring and adjusting frequency is gradually accelerated, which exponentially increases measuring and adjusting workload. A low cost whole process monitoring and control technology package for separated layer water injection was developed in this paper to tackle key problems about single-layer downhole flowrate measurement, layered adjustment and communication in wellbore, and to realize the digitalized real-time monitoring of separated layer pressure and injection rate for single well and the networking of dynamic water injection monitoring information on blocks and reservoirs. This technology was piloted in block. The pilot test block has small well spacing and fast breakthrough speed of injected water, where oil to be produced has greatly varied physical properties, and the production in different layers is unbalanced. In recent years, the water cut has increased fast, the annual water cut increase is above 0.8%, and the comprehensive water cut is 97.2%. By utilizing real-time monitoring and adjustment, effective water injection has been realized, and the increase of water cut has been maintained at less than 0.5% since one year ago when the block was selected for pilot test. Moreover, this technology is also provided with the functions of on-line seal check, static pressure test, water injection profile test and dynamic adjustment, and so site test and adjustment jobs can be minimized.