Publications

This study demonstrates that new 4D microgravity methods can be successfully applied for field water flood monitoring. An integration of 4D microgravity data, geological and geophysical data such as seismic data, open and cased hole logs, and field production data is used to monitor fluid migration in mature water floods to enhance injector-producer well alignment.Evolution in technology has yielded improvements in 4D microgravity methods as gravity meters have become much more sensitive and accurate. In 4D microgravity technology, data are measured repeatedly in the same location, with time offering the fourth dimension. “Anomaly gravity becomes the key as a relative measure with time. This measurement is caused by a density change in the subsurface that may reflect fluid replacement changes in the reservoir pore space as a result of fluid injection and migration.Our study was conducted within Area 4 of the Minas oil field where abundant fluids have been injected into the reservoirs. The challenge here is understanding fluid migration pathways. Considerable geoscience information such as open and cased hole logs, high resolution seismic, and detailed field production data are available for this part of the field. The study focused on combining these data with 4D microgravity data to understand the behavior of injected fluid and hydrocarbon movement.Gravity data were gathered twice, with a four month time lapse. The first data acquisition provided a base line and the second, a data set to observe gravity anomaly patterns. A planned third data acquisition will yield data for surveillance monitoring to understand and check previous results.This study has resulted in the generation of gravity anomaly maps, apparent saturation maps, and interpreted fluid movement and injection velocity profiles. These data were combined with other pertinent field data and previous study results to deliver a superior water flood management plan for a mature water flood field and also to identify bypassed oil.