Marine Technology Reporter Blogs - reservoirs

According to Petrobras production engineers, secondary recovery is increasingly being implemented to improve oil recovery in the pre-salt carbonates, where reservoir rocks are usually oil wet, and this characteristic affects the performance of water injection. Another problem concerning water injection is related to rock-fluid interaction, which is more important and complex in carbonates. In order to assess the risks involved, as well as to define mitigation actions, rock-fluid interaction tests are being carried out in the reservoir rock and the salt cap rock. Alternative recovery methods are being implemented in the pre-salt reservoirs.

Brazil is the largest country in South America and its oil and natural gas markets have expanded massively in recent years, causing the resurrection of its shipbuilding industry as a bonus. The challenging deepwater development projects have high priority in investments both is subsea technology for deepwater field development and onshore and offshore logistics infrastructure. In recent years Brazil has experienced rapid growth in the petroleum sector. O&G production went from 1.5 million barrels per day in 2001 to 2.4 million b/d in 2010. Offshore production accounted for almost 90% of this figure in 2010. Yet there have also been large onshore natural gas discoveries…

Statoil recently increased the estimates for their Campos Basin pre-salt O&G discoveries up to a substantial total of 1.24 billion barrels boe. Consequently Statoil has also increased its optimism for the geologically similar plays it has in Angola. Not only are the cross ocean plays geologically similar but they are also located along the same longitude. Both pre-salt geological formations off the Brazilian and West African coasts have their origins in common, something that goes back around 120 million years ago, when ancient Gondwana split into what is now known as South America and Africa. The pre-salt reservoirs on both sides of the Atlantic Ocean are expected to contain large quantities of light oil.

The Remus 6000 AUV was designed and developed by a partnership between the Naval Oceanographic Office, the Office of Naval Research and the Woods Hole Oceanographic Institute (WHOI). The Hydroid Inc, is young company, which was founded in 2001 by the inventors of REMUS to commercialize their product and to allow this ultra-deepwater AUV technology to reach a wider market and to guarantee funding for continuous product development. The REMUS AUV is the product of over 15 years of leading edge research and development. The REMUS 6000 is the deepwater version of the acclaimed Remus 100, lightweight, shallow water AUV and the Remus 600 deep water AUV.

Enhanced Oil Recovery (EOR) can increase the volume of recovered oil from a well mainly through the use of two distinct techniques. One is water injection, which is increasingly being used in mature fields and another is CO2 injection which is mostly used in deepwater fields and according to Petrobras will be extensively used at many of the pre-salt fields in Brazil, as these fields usually contain significant amounts of CO2 along with oil and gas. These are secondary production processes. The production process always refers to oil that is recovered naturally from a producing well, that is without the use of pressure or flow stimulants, such as water or CO2.

PRAVAP (Advanced Oil Recovery Program) began in 1993, when there was a need to create technological projects for the company to increase the recovery factor of its fields, prolonging its production on an economic and environmentally correct basis. PRAVAP main objectives are to provide and advance technological solutions that increase the recovery factor of oil fields, for optimum economy and permit exploration of fields considered under-commercial due to restrictions in existing technology. PRAVAP is organized in systemic projects, which are groups of research projects with a common objective. Wells - Its focus is on various technologies applicable in the well-formation interface…

Subsea gas-liquid separation coupled with liquid boosting can be an effective means of oil reservoir exploitation. Despite advances, multiphase pumping technology remains limited in its capabilities. Dynamic (centrifugal and helico-axial) pumps function with reasonable efficiency for single-phase, low-viscosity liquids. However, they become very inefficient when a high-viscosity liquid is combined with high percentages of free gas. While use of multiphase pumps is in many instances an effective solution, special consideration must be taken when challenging conditions exist such as are found in deeper water or with long tieback distances, or when heavy-oil production is involved. More effective oil reservoir exploitation can be achieved using subsea separation coupled with liquid boosting.