Presenter
Darling Criollo from Halliburton
Co-authors
Equinor
Abstract
INTRODUCTION
Integrated project with the aim to maximize customer reservoir understanding of a production field in Norway. The use of three different technologies evolves from qualitative to quantitative application. Advanced Mud Gas (AMG) as the cost-effective solution for near real time analysis for fluid characterization and contacts identification. Ultra Deep Azimuthal Resistivity (UDAR) tool to monitor vertical and lateral limits of the reservoir and assess the oil water contact (OWC). Ultrasonic High-Resolution borehole image tool to detect bedding, fractures and faults planes.
METHODS, PROCEDURE, PROCESS
This project integrated the solution of advanced degasser to obtain recycle and extraction efficiency correction (EEC) of methane to pentane species. The gas ratios were applied holistically to Geosteering UDAR inversion curves, plus the communication protocol played an important role for the operator team to successfully navigate the well. Ultrasonic High-Resolution analysis was carried on detecting structural and sedimentologist changes in the target sandstones, several diagrams such as Stereonet and Walkout plots were done, in addition, an ultrasonic caliper was analyzed to identify the borehole shape. A Petrophysical analysis complements and fits the results from AMG, UDAR and borehole image analysis.
RESULTS, OBSERVATIONS
The real time AMG EEC results provide a first look of the pressure/volume/temperature (PVT), therefore the ability to distinguish between oil and gas. The model proposed by Yang et al., 2019 of GOR (Gas Oil Ratio) prediction based on AMG data is applied in this case study, showing the real time contribution. The heavies species also contribute for water bearing identification, and in conjunction with the geoscience integration, results confirmed water in advance what later production strategy decided by blanking a 300m of identified water bearing zones. The UDAR data improved the reservoir insight by unveiling the presence of unexpected water channels driven by lithology and fluid contact movement.
The sandstone bedding plane orientation showed several trends inside the whole interval and most of these changes were associated with faulted intervals and validated with Geosteering inversion model. The fault system comprehension is useful in this basin since it contains a western graben created by several faults stepping down preserving the Upper Brent. The basin setup is helpful to understand the fluid distribution in this petroleum system. From petrophysical viewpoint, water saturation from resistivity logs and neutron-density separation helped to estimate fluid types and it was validated with AMG.
CONCLUSIONS
The insight of this holistic approach among AMG, Geosteer, and HR ultrasonic image LWD data from three wells drilled in this project signified a promising beginning for combining fluid-related data, like advanced gas logs, with geological features such as the HR ultrasonic image data and the geosteering model that allows the analysis from a macro scale of the geology and fluids present. Therefore, this study leads to several key conclusions as highlighted below.
Given the variability of the expected scenarios, the UDAR modeling proved crucial to define the optimal UDAR tool configuration. Based on that, the predefined UDAR inversion settings allowed to identify multiple hydrocarbon and flooded intervals.
The rich gas interval was constantly mapped around the well, associated to high resistivity values in the inverted models. Furthermore, an unexpected water channel geometry was defined with the UDAR inversion data providing insight of the complexity of the flooded intervals.
The AMG data, a cost-effective solution, played an important role toward real time decisions and post analysis. The real time analysis was able to give fluid type, GOR and density prediction, helping with the petrophysical interpretation of the section. The confirmation of the GOC helped decision making changes of the well trajectory.
Biography
Petroleum Engineer with 15 years of experience specializing in ultrasonic image analysis, petrophysical interpretation, well correlation, iso-property mapping, and unconventional reservoir evaluation. Proficient in processing and interpreting special logs using DSPetrophysics, Landmark (Halliburton), and Geolog softwares.
Passionate about geomechanics and integrating Python into petrophysical workflows. Focused on delivering efficient, high-impact solutions with a strong emphasis on Formation Evaluation Integration Analysis.