The Greater Burgan field is under production for more than 60 years and producing light to medium API oil. The objective of this paper is to explain an innovative method adopted in testing of Lower Burgan formation heavy oil and challenges faced during testing.

Heavy-oil zones are identified based on petrophysical logs interpretation and are located mostly near regional original oil-water-contact (OOWC). A previous study done on mapping of heavy oil zone for Burgan reservoirs and based on the maps, new process helped to identify expected heavy Oil zones in the upcoming and existing wells. To sustain future production target raised a need to explore flow potentials in the heavy oil reservoirs. A new methodology was developed by using a specially designed electrical submersible pump (ESP). Special testing pump (ESP) was designed and configured based on low API, high viscous oil, high angle deviation and reservoir characteristics from nearby wells.

The well was tested using specially designed ESP. The well produced for few days with Oil API 19-20 and flowed with a rate of 650-800 BLPD with 40%-50% water cut. In the future, this zone could be put back on production.

Earlier for heavy oil Burgan reservoirs, the oil viscosity and density were measured from downhole fluid sampling in few of the wells. However, there are uncertainties on how oil properties change with pressure. For the first time in Greater Burgan field, using specially designed ESP was a remarkable success for initial testing of heavy oil reservoir close to regional OWC.

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