Insights from Process-Based Models and Integration with Reservoir Characterization and Rock Typing Workflows for the Pre-Salt Lacustrine Carbonate Reservoirs

2021 ◽  
Author(s):  
E. Pedersen ◽  
L. Leon Rodriguez ◽  
G. Jones ◽  
H. Qualman
Keyword(s):  
Reservoir Characterization ◽  
Carbonate Reservoirs ◽  
Rock Typing ◽  
Lacustrine Carbonate ◽  
Process Based Models

Carbonate Reservoir Characterization with High-Resolution Logging-While-Drilling Dual-Images in Oil-Based Mud

2021 ◽  
Author(s):  
Shiduo Yang ◽  
Thilo M. Brill ◽  
Alexandre Abellan ◽  
Chandramani Shrivastava ◽  
Sudipan Shasmal
Keyword(s):  
High Resolution ◽  
Reservoir Characterization ◽  
Early Stage ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Secondary Porosity ◽  
Rock Typing ◽  
Logging While Drilling ◽  
Dual Images ◽  
Ultrasonic Images

Abstract Fracture evaluation and vuggy feature understanding are of prime importance in carbonate reservoirs. Commonly the related features are extracted from high resolution borehole images in water-based mud environments. To reduce the formation damage from drilling fluids, many wells are drilled with oil-based muds (OBM) in carbonate reservoirs. There are no appropriate measurements to resolve the reservoir characterization in OBM with the existing technologies in horizontal wells—especially in real-time—to make decisions at an early stage. In this paper, we would like to introduce a workflow for geological characterization using a new dual-images logging while drilling tool in oil-based mud. This new tool provides high resolution resistivity and ultrasonic images at the same time. Structural features, such as bedding boundaries, faults, fractures can be identified efficiently from resistivity images; while detailed sedimentary features, for example, cross beddings, vugs, stylolite are easily characterized using ultrasonic images. Benefiting from the dual images, an innovative workflow was proposed to estimate the vug feature more accurately; and the fractures can be identified from images and classified based on tool measurement principles. One case study from the Middle East demonstrated the benefits of this new measurement. A near well structure model was constructed from bed boundaries picked from borehole images. The fractures were picked and classified confidently using the dual images. Additionally, fracture density statistics are available along the well trajectory. The vug features were extracted efficiently, which indicates the secondary porosity development information. Rock typing is achieved by combining fracture and vug analysis to provide zonation for completion and production stimulation. The dual-images provide the capability for geological characterization in carbonate reservoir in an oil-based mud environment. The image-based rock typing helps segment the drain-hole for completion and production stimulation. The reservoir mapping with rock typing provides detailed information for in-filling well design.

Ultra-deepwater seismic plays offshore Brazil — Future drilling off Santos and Campos Basins

2019 ◽  
Vol 7 (4) ◽  
pp. SH99-SH109
Author(s):  
Roberto Fainstein ◽  
Ana Krueger ◽  
Webster Ueipass Mohriak
Keyword(s):  
Data Acquisition ◽  
Reservoir Characterization ◽  
Carbonate Reservoirs ◽  
Source Rocks ◽  
Brazilian Coast ◽  
Depth Migration ◽  
3D Data ◽  
Shelf Slope ◽  
Seismic Amplitudes

Contemporaneous seismic data acquisition in the Santos and Campos Basins offshore Brazil have focused on image characterization of deepwater and ultra-deepwater reservoirs and their relationship with hydrocarbons originating from synrift source rocks. Our interpretation has mapped the stratigraphy of postsalt turbidite reservoirs, and, on the presalt lithology, it has uncovered the underlying synrift sequences that embrace oil-bearing source rocks and the prolific, recently discovered, microbialite carbonate reservoirs. The new phase in geophysical data acquisition and offshore drilling that started in 1999 bolstered the Brazilian offshore petroleum production to record levels. The new, massive, nonexclusive, speculative 2D and 3D data acquisition surveys conducted offshore the Brazilian coast far exceed the amount of all existing cumulative vintage data. Deepwater drilling programs probed the interpreted new prospects. As whole, the modern geophysics data libraries offshore Brazil brought in the technology era to seismic interpretation, reservoir characterization, and geosteering operations in deepwater development drilling. Still, regional interpretation mapping of the outer shelf, slope, deepwater and ultra-deepwater provinces of the Santos and Campos Basins indicates plenty of prospective future drilling in the salt locked minibasins of the ultra-deepwater provinces. Salt tectonics shapes the architecture of these basins; hence, postsalt deepwater turbidite plays were readily interpreted from seismic amplitudes of the modern data that also allow for resolution images of the synrift source rocks, salt architecture, migration paths through faulting and salt windows, reservoir characterization, and regional seal mapping. The new techniques of prestack depth migration have enabled uncovering the imaging structure of the synrift that led to characterization of the presalt carbonate reservoirs and discovery of giant accumulations. Future offshore exploration will continue aiming at postsalt deepwater and ultra-deepwater minibasins plus presalt plays under the massive salt walls, still an underexplored frontier.

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