Presenter
Daria Latypova from Halliburton
Co-authors
Luis Chacin, Halliburton, Roxane Del Negro, Jørgen Håstø Borgenvik, Stefano Maiorano, Vår Energi ASA
Abstract
There are fewer undeveloped massive reservoirs available on the Norwegian Continental Shelf (NCS), therefore operators are deploying the latest in drilling technologies, to provide solutions to optimize drilling and completion in depleted reservoirs. In the Balder field, the complex network of Paleocene and Eocene remobilized injected sands dictates further field development with multilateral (MLT) wells. Three-dimensional (3D) Ultra Deep Azimuthal Resistivity (UDAR) technology is a key factor to turn this approach into reality, to optimize the placement of the MLT junctions.
The Balder production started in 1999 and is supported by a strong natural aquifer drive and water injection. One of the main challenges of the Balder field is the reservoir architecture mapping, due to the complex injectites geometries, moved fluid contacts and remaining thin targets. To derisk the targets potential, the integration of seismic data, conventional logging and UDAR technologies are necessary. One-dimensional (1D) electromagnetic (EM) inversions are often affected by lateral resistivity variations due to the characteristic 3D nature of the injectites. UDAR images are commonly useful as a qualitative indication of the injected sand distribution, but do not provide distance to boundaries. It is only with the use of a fully 3D solution that the measurement and quantification of the injectite system and complex fluid distribution surrounding the wellbore can be realized.
This case study is an analysis of 1D and 3D UDAR inversions implemented for the planning and execution of a two-legged MLT well in an injectite setting. The successful installation of the MLT junction required defined prerequisites to be fulfilled, with the biggest challenge being the presence of “clean” sand, with no embedded clay, around the milling window to avoid the risk of wellbore collapse. The extensive radius of investigation of 27m of the inverted 3D volume allowed for detailed mapping of the zone of interest to optimize the junction placement. As a result, the window was placed precisely, leading to successful sidetracking and efficient drilling and completion of the second leg. With both legs overlapping initially within the UDAR radius of investigation, one main sand body was identified.
This is the first time that a fully-3D UDAR solution has been utilized for MLT well construction in the Balder Field. This case study opens the door for successful implementation of MLT well design in the future development of the Balder area and similar fields.
Biography
Daria holds bachelor degree in geology and master degree in geophysics. She started her career in 2012 when she joined Schlumberger as Well Placement engineer. She has been working on a big variety of projects worldwide since then. In 2023 she joined Halliburton as a Senior Geosteering Geologiest, working with Vår Energi.