Triple-Zone Intelligent Completions Aid Extended Well Tests of Exploratory Wells
Authors: Wilson Adam 
Published: April 2018

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper OTC 28103, “Intelligent Completions Used During Extended Well Test of Exploratory Wells in Brazil,” by L. Costa, D. Rodrigues, R. da Silva, I. Souza, and M.A. Fernandes, Halliburton, prepared for the 2017 Offshore Technology Conference Brasil, Rio de Janeiro, 24–26 October. The paper has not been peer reviewed. Copyright 2017 Offshore Technology Conference. Reproduced by permission.

This paper describes an extended-well-test campaign using intelligent completions in a presalt reservoir. To understand reservoir behavior during production better, several options were analyzed for the first extended well test. Drilling wells provides valuable rock and formation knowledge; however, this information is not sufficient to simulate formation-flow behavior during the field life cycle and reduce production uncertainties. A triple-zone intelligent completion was envisioned as the optimal solution to understand how each interval would behave under production or injection.

Introduction

Presalt represents an important driver of the oil industry in Brazil because it is responsible for a large percentage of the total oil being produced in the country. In 2010, the discovery of a new and gigantic field (estimated at 8 billion bbl) increased the importance of the presalt polygon for the region, and it was considered a watershed in terms of the country’s economy, intensifying oil-industry activities at the time. The field, in the Santos Basin, is approximately 140 miles offshore Rio de Janeiro (Fig. 1).

According to Brazil’s National Agency of Petroleum, available field resources can vary from 8 billion to 12 billion bbl, while the production per day can reach up to 1.4 million bbl. With these significant numbers, field exploration and production became the focus of a main operator in Brazil.

Well Testing: An Important Step Before Production

Understanding the reservoir is fundamental to improving recovery and production performance. Poor decisions regarding this information can affect the final result directly. Some of the information necessary to understand a reservoir is obtained during the drilling and evaluation of wells. However, well testing escalates reservoir analysis to a higher level in terms of details. The more accurately data are acquired during the exploratory phase of the field, the better the reservoir models can be, resulting in optimal completion plans. During this particular project, the operator decided to perform extended well testing in three exploration wells, an injector and two producers.

This strategy was implemented successfully by the operator in previous deepwater reservoirs. Extended well testing provided key information for field development in those reservoirs, and it came to be considered essential for similar future projects. The primary difference between those extended well tests and the one discussed in this paper is the use of intelligent-completion equipment installed in each well. The equipment allows the operator to evaluate each zone with detailed data provided in real time.