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Spotlight

Mapping While Drilling Service

Wed, 01/20/2016 - 11:07

Schlumberger’s GeoSphere service uses deep, directional electromagnetic measurements to reveal subsurfacebedding and fluid-contact details more than 100ft from the wellborn. Allowing operators to map while drilling, this service provides a depth of investigation that changes the game for steering capabilities within complex reservoirs. Typical logging-while-drilling measurements detect only the first nearby geological boundary, while the GeoSphere service’s scope maps reservoir layers in the horizontal section over 100ft around the wellbore. In fact, operators have successfully mapped the upper and lower boundaries of a reservoir simultaneously in real time. The acquired data enables an accurate prediction of upcoming strata or formations in both high-angle and horizontal wells. Geoscientists and drilling engineers can then interpret reservoir data and steer wells for maximum reservoir exposure.

The GeoSphere mapping-while-drilling service can also improve well-landing operations, reducing drilling risks, eliminating the need for pilot holes, and increasing reservoir exposure. Pilot holes are often used to evaluate formations before landing the horizontal, but this costly method does not always mitigate risks in complex reservoirs where shallow or deep landings can occur. In the case of a shallow landing, a long part of the reservoir section is drilled in the overburden, compromising lateral exposure and impacting well productivity. Likewise, drilling a tight inclination above the reservoir also makes completion operations challenging; landing too deep creates a slump in the wellbore that can lead to early water breakthrough or more attic oil. Furthermore, a high pressure difference between the overburden rock and the top of the reservoir can lead to severe well integrity risks. Due to its accurate mapping capabilities, the GeoSphere service helps ensure optimal landing by extending the radial depth of investigation more than 100ft around the wellbore.

In addition, the GeoSphere service reveals subsurface layers and fluid contents at the reservoir scale, which has a significant impact on field development strategies. Real-time mapping data enables operators to stay in the sweet spot by steering the well strategically and avoiding unplanned reservoir exits. Conventionally, loggingwhile-drilling tools provide downhole measurements a few inches from the wellbore, but GeoSphere’s 100-feet scope improves reservoir characterization and reduces geological uncertainties. Data provided by the service can be integrated with seismic data to help operational engineers analyze the reservoir, adjust well paths while drilling, and deliver smoother wellbores. The GeoSphere mapping-while-drilling service reveals subsurface details at the reservoir scale to help refine geological and structural models, ultimately enabling operators to maximize production.