oa New Workflow for a Mature Field: Synergy of Dowhnole and Surface Fluid Loggings Enhances Oil Recovery and Derisk Sampling Operations

Production of the remaining oil from a mature field presents many challenges due to the movement of the gas cap and the water table. Moreover, the geological reservoir behavior might cause wellbore instability issues that complicate drilling operations.

This paper presents a new workflow for enhancing the real-time fluid characterization by combining advanced mud gas (AMG) with downhole fluid mapping-while-drilling (FMWD). The two technologies are usually used for optimizing the depth of sampling, while the new workflow boosts the power of the two technologies to reduce the stationary time on each station while improving the data quality. This paper also presents information useful to those who are planning the identification of and consequent production of the last hydrocarbons rims in a brown field to optimize the resources and leverage their outputs.

AMG provided a first insight of the fluid composition, together with the GOR estimation while drilling, and a comparison point to the original and offset wells’ pressure/volume/temperature (PVT) data. FMWD confirmed pressure regimes, producibility and movable phase indication. Using AMG during the FMWD operation, allowed for meaningful characterization of the hydrocarbons while limiting the stationary time, reducing the risk of stuck pipe.