Time lapse (4D) Seismic Monitoring of Water Front in a Compacting Carbonate Gas Field, Offshore Myanmar

Time lapse seismic plays critical roles in reservoir monitoring not only in the traditional clastic reservoirs but also in increasingly important carbonate fields for optimized field development. In this case study, 4D seismic has been used on Yadana Field, offshore Myanmar for a critical monitoring of the gas water contact rise in the field. Yadana Field first and second seismic monitors were acquired in 2012 and 2018 respectively. In particular, the second monitor was used to quickly assess water front movement and evaluate in-fill well opportunities. The monitoring seismic campaigns have been very successful as clear 4D signals corresponding to the evolution of the producing gas water contact is identified on the Monitor1-Monitor2 increment and shows a good fit with well information (RSTs and water breakthroughs) as well as a remarkable complementarity with the first monitor information (GWC rise-up previously interpreted on Base-Monitor1 first time-lapse). Additionally, 4D warping and inversion allowed for the computation of remaining gas column and reservoir model update.