Acquiring samples earlier in a well plan minimizes reservoir uncertainty and enables better planning for future activities. The deployment of a logging while drilling (LWD) fluid analysis and sampling tool in this scenario enables the operator to mitigate the risk of data acquisition and improves access to challenging boreholes including deviated wells and extended reach drilling.

This paper discusses the deployment of a LWD formation pressure testing and sampling tool in a high angle well in Asia Pacific. The objective was to collect representative gas samples for geochemical analysis and proper facilities design. Therefore large representative sample volumes of up to twenty liters were required to ensure a proper lab analysis of the reservoir fluid properties. These samples were taken in two different wells during dedicated sampling while drilling runs.

The highest priority was maintaining the chemical composition of the sample as close to in-situ condition as possible. Consequently, a minimized chemical adsorption within the tool's metallurgy was required. Although the metallurgy of the tool and the tank systems are inert to adsorption of most geochemicals in reservoir fluids, it was decided to apply a coating to some of the tanks.

The contamination level during the clean-up process while sampling gas is difficult to predict because an emulsion may be generated that masks the clean-up response and gas signature of the sensors during fluid analysis. One of the recent improvements to the LWD fluid analysis and sampling service is real time mobility and compressibility measurement. These two measurements are solely based on the pump system and not adversely affected by immiscible fluids. It will be discussed how the clean-up process can be improved furthermore without adding tool functionality and increasing the service complexity.

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