Tía Juana

Tía Juana Oil Field Profile

Location and Geography

The Tía Juana Oil Field is located in western Venezuela, specifically in the Zulia state, near the shores of Lake Maracaibo. The field's approximate coordinates are 9.8950, -72.0860.

Operator and Ownership

The Tía Juana Oil Field is operated by Petróleos de Venezuela, S.A. (PDVSA), the state-owned oil company of Venezuela.

Discovery and Production

The Tía Juana Oil Field was discovered in 1925. While the exact year of production start is not specified, it has been in operation for several decades.

Geology and Reservoir Characteristics

The oil deposits in the Tía Juana field are found in the Lagunillas Formation. The reservoir is composed of channels with the top of the reservoir ranging from 450 to 1000 feet. The total thickness of the Lagunillas formation averages 280 feet and is divided into two main layers, with the top layer being 40-85 feet thick and characterized by homogeneous rock (99% quartz).

Oil Characteristics

The Tía Juana field contains heavy oil with an API gravity of 9-11° and a relatively high viscosity, ranging from 10,000 to 45,000 centipoise at 110°F. This type of oil has historically shown low recovery rates using conventional methods.

Extraction Methods

Given the heavy and viscous nature of the oil, the field has been the site for several advanced extraction techniques:

• Cyclic Steam Stimulation (CSS): This method has been used but has shown lower efficiency in the northern part of the field where viscosity is higher.
• Steam-Assisted Gravity Drainage (SAGD): A pilot project for SAGD was implemented in 1987 and later expanded in 1997. This method involves using parallel horizontal wells to inject steam, which significantly improved recovery factors to between 52% and 60%, a substantial increase over the 10% recovery rate with CSS.

Production and Reserves

• Production: The field produces approximately 35 million barrels of oil per year (as of 2015) and 79 million barrels of total liquids per year (as of 2004).
• Reserves: The 1P (proven) reserves for oil are estimated at 3,929 million barrels, and for total liquids, they are estimated at 5,112 million barrels (as of 2004 and 2015 respectively).

Infrastructure

The Tía Juana field is connected to several oil pipelines operated by PDVSA, including the Ule-Amuay 2 Oil Pipeline and the Ule-Amuay Oil Pipeline, which transport oil from Tía Juana, Zulia, to Carirubana, Falcón.

Pilot Projects and Innovations

• A SAGD pilot project was successfully implemented, showing initial production rates better than expected (700 BPD vs 300 BPD estimated). Long-term production rates aligned with numerical simulations, and the process required significantly less steam than other methods.
• Another innovation involved the simultaneous injection of steam and solvent (using industrial diesel as a solvent), which increased the average initial oil displacement efficiency.

Challenges and Factors Affecting Operations

The Venezuelan energy sector, including the Tía Juana Oil Field, faces several challenges such as government mismanagement, international sanctions, and economic instability. These factors have severely hampered the overall efficiency and output of the field.