New Generation of Formation Testers – New Horizons: First Experience in Russia

Abstract

As the production of oil and gas in major regions has been declining, exploration efforts are shifting towards hard-to-reach understudied areas with lack of necessary infrastructure. In addition to that, hydrocarbon fields that are being explored today, typically have more complex geological structure than the ones discovered decades ago and are characterized by the presence of multiple reservoirs with individual fluid contacts. The abovementioned reasons cause significant increase in time required to test these reservoirs and estimate their production potential. Therefore, there is a real need for reliable technologies that would expedite the testing of such complex fields. New wireline formation testing platform has an updated hardware architecture enabling to use it for both traditional formations testing applications as well as the development of new testing procedures deviating from conventional practices. This paper describes the novel testing approach implying the use of wireline formation tester (WFT) in conjunction with a surface multiphase flowmeter, which was implemented at one of the large gas fields located on the Gydan peninsula. A key feature of the new formation testing platform compared to its predecessors is its ability to pump an order of magnitude greater volumes of reservoir fluids, which allows to estimate permeability in the uninvaded zone of the reservoirs and their productivity. Combination of the wireline formation tester with the surface multiphase flowmeter enables measuring surface rates and capture surface samples of reservoir fluids thus making this type of testing comparable to traditional well testing. At the beginning of the paper we provide a brief description of the acquired formation testing results with stress on key features of the new wireline formation testing platform. The rest of the paper is devoted to Deep Transient Testing (DTT), more specifically, to its design and planning, required hardware and description of results acquired during such tests. We also demonstrate an approach that can be used to estimate reservoir productivity based on the obtained data.