The frequent inclusion of all the latest acquired data into the static and dynamic models is a leading best practice for fields in the early stages of production. Since new decisions are taken continuously, it is clearly preferable to have reservoir models available that contain the most updated understanding of the subsurface. Peregrino field is a sandstone reservoir, located offshore in the Campos Basin, with heavy oil characteristics and started its production in 2011. Nine wells were drilled in the first production year, seven wells drilled in 2012 and eight wells will be drilled in 2013. This involves a vast amount of new data being acquired both while drilling and during production. The data from the new wells needs to be made into information that can be used to improve well placement and the drainage strategy, always on time for the upcoming decisions. Also production data should be regularly considered in the model updating and used for history-matching, especially when new events like water breakthrough and pressure decline are observed. This paper will give an overview of the methodology implemented in the Peregrino field in order to deal with these challenges. An integrated workflow has been used to keep the models consistent with new well observations such as structural tops, sand content and petrophysical properties and to ensure reservoir models updated on useful time. Also, new production data is being matched by updating uncertain parameters such as depth conversion, facies proportions, variogram lengths, oil-water contact, faults properties, relative permeability curves and KvKh, in a big-loop setup for history matching. The final product of the methodology described is an ensemble of history matched reservoir models, created in a short period of time and using all the new data available. These models can be applied directly to calculate P10, P90 and mean profiles for new well locations, new projects or for updating the field production forecast. Considering the delivery time of these results and the solid structure of the workflow, the Peregrino field is ready for the challenge of keeping reliable models under the scenario of continuous information update. Introduction The Peregrino Field is located in Block BM-C-7, in the southernmost Campos basin offshore Brazil as shown in Figure 1. The area is located 85 km southeast of the nearest coastline, approximately 100 km southeast of Macaé. Statoil is the operator and holds a 60% ownership in the field while Sinochem is the sole partner holding the remaining 40% ownership. Peregrino has large volumes of oil in place, over 2 billion barrels, in the currently developed area of the field, which are found in a heterogeneous sandstone reservoir. The reservoir interval is the Carapebus Fm., with good quality Cretaceous sands deposited from gravity flows in deltaic and shallow marine environments. The upper and lower parts of the reservoir are divided by a 5 meter thick siltstone flooding surface. The oil viscosity at Peregrino varies from 100 cP to 400 cP, and the average density is 14°API. This makes Peregrino one of the heaviest offshore oil developments in Brazil.
The Peregrino Field is an accumulation of 13-16° API oil in the Carapebus Formation in the Campos Basin and is thereby one of the heaviest oil offshore developments in Brazil. The field was discovered in 1994 and in 2007 Statoil became a Peregrino partner followed by Peregrino operatorship in 2008. The field has been in production since 2011 by using two well head drilling platforms and one FPSO in water depth ranging between 95 to 135 m. There are 45 production and injection wells drilled so far and 15 remaining slots on the platforms. The Peregrino recovery mechanism is mainly based on reservoir depletion and rock compaction combined with aquifer pressure support and produced water reinjection in the water and oil zones. The viscosity difference between oil and water at Peregrino gives an unfavorable mobility ratio, and water flows with a higher velocity than the oil. Any means to limit the water flow from the wells may enable an optimization of oil production. In 2013, a technology qualification program was conducted to qualify both Inflow Control Devices (ICD) and Autonomous Inflow Control Devices (AICD) technologies for use at Peregrino. Since then 2 wells have been equipped with ICDs and 7 with AICDs. The production experience from those ICD/AICD wells shows that the device is best suited in areas with good pressure support, high productivity index (PI) and heterogeneous reservoir. The paper will cover a comprehensive evaluation done for the ICD/AICD wells in Peregrino focusing on subsurface data challenges and performance predictions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.