Extend the lifespan of a reservoir through heavy oil development while reducing environmental impact
The exploitation of heavy oil faces two crucial challenges: reducing the cost of production per barrel; and increasing the recovery factor to extend the productive life of the reservoir. Both of these must be tackled while working to leave no environmental footprint.
Technological developments have played a fundamental role in increasing well production in areas such as the Orinoco Oil Belt in Venezuela, where the increase since 1970 has been more than an order of magnitude. This improvement is attributable to widely used technologies such as horizontal wells, multilateral wells, different types of gravel pack, progressive cavity and electro-submersible pumps, and diluent injection.
These technological developments have also led to a substantial reduction in production costs. Today, the production of heavy oils can be profitable, particularly in the case of young reservoirs with relatively low-viscosity oils, and where water has not exhibited substantial breakthrough.
Enhanced oil recovery (EOR) has been used for decades to increase the recovery factor and extend the reservoir’s lifespan. Traditionally, steam injection, in its various forms, has been the most commonly used. Newer methods such as polymer injection have been tested recently in the field, for potential use in reservoirs involving very thin or very deep sands. Polymers can be used to approximately 9,000 feet in depth, regardless of the thickness of the sand.
Many EOR methods are currently in development and field-testing stage, including in situ reaction, downhole upgrading and the use of microorganisms.
Water production is inevitable, and controlling it is of fundamental importance. On one hand are environmental concerns and handling costs at surface; on the other is the ability to expand reservoir lifespan. Chemical products such as FormSeal®, which are used to shut off water, have evolved significantly to become environmentally friendly, with toxicity and bioaccumulation at very reduced levels. The use of mechanical inflow control devices (ICDs) and the recently developed autonomous version (AICD) are also important contributions to addressing the challenge of water production.
New methodologies like the Decision Management SystemTM, along with smart algorithms and stochastic analysis technologies, have been proven to substantially improve:
- integration across disciplines such as earth science, reservoir, drilling, economics
- planning time
- selection of exploitation scenarios
These improvements can increase economic benefits and reduce risk by more than 30 percent.
Significant developments that improve surveillance and operation control have been deployed in a variety of settings. Newer systems provide alerts to undesirable trends or events, making them particularly useful in remote areas, or where the large number of wells impairs the conventional surveillance-control systems.
Ever-expanding computing power is contributing to rapid progress in digitalizing heavy oil fields by making it easy to perform holistic surveillance in real time, diagnose wells and surface facilities, and provide subsurface-to-surface integrated numerical optimization. Operational response times are minimized, and the cycle time for updating models and injection-production-economy forecasts is substantially reduced. Each of these advances delivers clear economic benefits throughout the lifespan of the reservoir, and operational, safety and environmental risks can be prevented more effectively. Additionally, important developments have been achieved in areas such as California and Kuwait, where the trend is toward integrating all factors related to smart exploitation of heavy oil fields.
For decades, the environment has been a topic of persistent public concern. Operators and service companies have found solutions in innovative products and services like FullCircleTM Cuttings Re-Injection (CRI); low toxicity-biodegradable drilling muds (ACCOLADE™, ENCORE™); sand production control (PetroGuard ® Advanced Mesh); water production control (ICDs, AICDs, H2Zero™), and biocide-free water purification (CleanStream® Service). These and many other technologies enable them to fulfil strict environmental regulations in all countries where oil reserves are being developed.
The story does not end here. Service companies like Halliburton are working intensively with universities, research centers and operators to generate the new technologies that will even further improve all aspects of heavy oil development.