Short and Long term Management of El Furrial Field, Venezuela
Authors: Colmenares Rodolfo , Smith Richard W. 
Published: December 2007

The El Furrial Field, discovered in 1986, is one of the major oil field assets of Venezuela. Its current production of nearly 390,000 BOPD makes it a giant oil field based on world standards. Major development of the field to increase production to a target rate of 450,000 BOPD has been a priority for the last 5 years. In 1997, final stages to begin high pressure gas injection to augment water injection will be completed.

This paper presents the management considerations, economics, engineering and technical applications related to the history of the development of the field. Current understanding of the reservoir and production mechanisms show that original development expectations of the late eighties to early nineties fell short of the full potential of the field. Technical efforts have highlighted costly. but very economic, programs to increase production and reserves using state-of-the-art techniques for field management.

Plans are in place and work in progress for initiating final development and high pressure gas injection. The program under progress is the first of its kind in Venezuela where secondary and enhanced recovery techniques have been started before primary recovery was completed. The management of this field sets a standard in Venezuela for identifying the potential of an asset field and defining a program to maximize its potential.

Management of the field is centered on basic engineering and planning considerations which form a symbiotic relationship between managements' concern for fiscal planning, operations budgets, and major capital outlays. The project, as it is currently defined would not have been approved without very carefully planned and thought out programs combining all business and technical disciplines into one effort.

Introduction

El Furrial field is located in Monagas State, Venezuela, approximately 20 km. west of Maturin. It is associated with other fields along a trend of deep thrusted structures. Other fields associated with the same trend are the Orocual, and Soqueron fields to the east and north, and Carito, Carito Oeste, and Santa Barbara to the west. El Furrial field is characterized as a giant field with original oil in place (OOIP) in the Naricual formation estimated to be more than 6,000 MMSTB.

The field was discovered in 1986 with the exploratory well FUL-1. This well was drilled through the top of the Naricual Formation, discovering medium gravity oils with an API gravity of 28. The initial reservoir pressure of 11020 psi, corrected to datum at 13000 feet subsea(ss), (Measured Depth of approximately 13500) indicated significant over pressured conditions. Average reservoir temperature is approximately 300 F.

The field is approximately 13 km. along strike and 7 km wide. The field produces from two reservoirs identified as the Naricual and Los Jabillos Formations. The gross thickness of the two reservoirs is more than 1600 ft. (Please see Figure 1)

The field has been developed on an initial well spacing of approximately 1200 meters based on original reservoir definitions as Naricual Superior, Medio and Inferior, and Los Jabillos according to Venezuelan Ministry of Mines standards.

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