Petrobras . Pioneering Technologies For The Pre-salt
From our first deepwater discoveries in the Campos Basin, in the 70s, until reaching the new pre-salt exploratory frontier, we have a followed long technological journey. To overcome each of the challenges posed by previously unknown conditions, we were motivated to improve existing technologies and develop new solutions, together with our suppliers and partners.
The Offshore Technology Conference (OTC) has existed since 1969, and is the world's largest offshore oil and gas production business event. The OTC Distinguished Achievement Award for Companies, Organizations, and Institutions is the highest technology recognition an oil company can get as an offshore operator. Since the creation of the prize in 1971, only a handful of global petroleum companies have ever received this distinction a third time.
For the innovative technologies we developed with partners and suppliers, we were granted, at different moments in our history, three OTC awards:
Award for technical achievements related to the development of deepwater production systems in the Marlim field, in the Campos Basin. This set of projects made producing oil at a depth hitherto regarded as a record, about 700 meters, feasible.
Award for advances made in deepwater project technologies and cost-effectiveness in the development of the Roncador field, in the Campos Basin. It took 27 months from the discovery to the first oil, at a depth of over 1,800 meters.
Award for the set of technologies developed for producing in the pre-salt layer.
The technologies awarded by the OTC 2015 are part of a broad spectrum of successful decisions taken together with our partners that made it technologically and economically feasible to produce oil and gas in the Pre-Salt.
The 2006 discovery of these large oil and gas reserves along the southeastern coast of Brazil represented a new chapter in the global oil history. The new oil province ranges over an area measuring almost 800 km in length and contains reserves estimated at billions of barrels of light oil.
But the environment in which the new deposits were nestled brought about greater risks, in addition to transportation and logistical hurdles.
Face the harsher oceanographic conditions in the Santos Basin Pre-Salt Cluster, as compared to the conditions seen in the Campos Basin.
Produce oil and gas in a location to which access is limited and without pre-installed production infrastructure: 300 km off the coast, with water depth reaching 2,200 m and reservoirs nestled 5,000 m below the seabed, including a salt layer that is about 2,000 m thick.
Create technology able to withstand the high pressures in the reservoirs and the contaminants in the fluids produced.
The knowledge gained over decades of experience in the Campos Basin was instrumental in the development of new technologies. But the Pre-Salt challenge was entirely new. More than simply adapting existing technologies, it was necessary to devote time and resources to test new materials and solutions. For this, we relied on the participation of several technical areas of Petrobras, including our research center, Cenpes.
20 drilling rigs
47 support vessels
3 vessels used to lay pipes in ultra-deep waters (PLSV)
All this work has contributed to set new standards in drilling and completion, in subsea systems, and in mooring systems for platforms for the entire oil and gas industry.
Time between the completion of the first test well at the Lula Field (October 17, 2006) and the first oil lifted in the extended well test (May 1, 2009) in ultra-deep Santos Basin waters.
Average time to build an offshore well in the Santos Basin pre-salt cluster in the first five months of 2016. In 2010, the average used to be about 310 days, a term that had dropped to 128 days in 2015.
Since 2010, we have continuously reduced the total well drilling and completion time.
The annual average output operated in the pre-salt in 2015 was the largest in our history.
We surpassed this daily output level in the pre-salt, together with our partners, on May 8, 2016.
The technologies that enabled production in the inhospitable pre-salt conditions have been tested, proven, and today represent an important legacy for the oil industry.
Highlights include the development of different subsea collection pipeline system solutions, new well construction solutions, and the design of CO2 separation and injection systems to face the challenge of not releasing the CO2 that is produced to the atmosphere.
Risers are pipelines that take oil or gas from the seabed to the platform.
In order to sustain the risers that are connected to the wells' subsea pipelines, buoys are installed at a point between the seabedOcean floor, bottom of the sea. and the surface of the sea (about 250 meters in depth). This allows them to be connected to the FPSOs (floating production, storage and offloading units) through flexible tube spans.
With this setup, the floating platform's movements are not transferred in full to the rigid risers, reducing the damage caused by fatigue and ensuring their useful life even under severe meteocean conditions.
Two buoys were installed in the pilot project carried out for the Sapinhoá field and two in the Lula field (in the pilot project for the Lula Nordeste area), for a total of nine wells currently in production.
Rigid risers called Steel Catenary Risers (SCR) have been installed supported directly on the Buoy Supporting Risers (BSR). These were the first of the SCR-type risers that used carbon steel pipes lined internally with a corrosion-resistant metallic linerMetallic lining for the internal protection of steel pipes..
Special procedures and qualification tests enabled the use of these pipes under dynamic conditions (such as risers) and enabled installation using the reel layMethod of launching lines using vessels equipped with reels. This has the advantage of installing pipelines on the seabed at a higher speed than conventional methods. method.
Approximately 100 km of these tubes with metal liners were used in the Sapinhoá and Lula NE Pilot Projects.
Steel Lazy Wave Risers (SLWR) are steel risers that are installed with a set of floats that form a humped configuration and are connected directly to the floating production unit. This is the first system of its kind in the world to be connected to an FPSO with spread mooring designed and built to withstand the movements of the vessel platform in the adverse pre-salt environment.
The first SLWR deployed in the pre-salt is at a water depth of 2,140 m, interconnected to FPSO Cidade de Ilhabela (Sapinhoá Norte project).
The flexible riser consists of a multilayer pipe (parts made of metallic material and parts made of polymeric material) that transfers the oil and/or gas from the well on the seabed to the production platform. To operate in the pre-salt, it underwent specific development to meet the conditions in corrosive atmospheres and ultra-deep waters.
The flexible riser operating at the greatest depth (7,021 ft) was installed in the Lula field, in the Iracema Sul project. There are already more than 35 flexible risers operating in the Santos Basin, producing oil and natural gas.
System based on optical fibers that are attached to the flexible risers' tensile armor wiresSet of wires that form the layer of the flexible duct responsible for resisting tensile loads, such as its own weight.. The system allows identifying wire breaks, sending warning signals in order for maintenance actions to be taken to keep damage from spreading.
The risers are already being installed with coupled sensors to be connected to the control room on the platform.
During the well construction process, a fluid known as drilling mud is put into the borehole to maintain pressure, keep its walls from collapsing, and to take gravel to the surface. In a few rock sections where there are fractures or caves, drilling mud seeps into the rock - a phenomenon known as "loss of circulation" -, rendering well progress difficult or even preventing it. The use of the PMCD technology enables drilling in this scenario and reduces time loss.
This technology was used in an unprecedented way in terms of depth at the Lula-19 well, in the midst of a scenario characterized by large losses of circulation, where conventional drilling is not feasible.
Completion is the setting up of materials and equipment in an oil well to produce or inject fluids. Effective reservoir management with intelligent completion allows the increase of the end oil and gas recovery factorAmount of oil that can be extracted of the total contained in the reservoir. from the reservoir.
The intelligent completion technology has been used intensively in the pre-salt, having been installed at 22 wells until March 2015.
In a few pre-salt wells, the oil that is produced is associated not only with water and natural gas, but also with CO2. The CO2 that is produced is separated from the oil and natural gas using a sophisticated membrane system that separates carbon dioxide molecules from the other fluids through the selective permeationof gas molecules (H2S, CO2, CH4, etc.) by the plastic seal layer.. Once separated, the CO2 is re-injected to increase pressure in the reservoirs and well productivity and to decrease greenhouse gas emissions.
We use this separation technology and CO2 reinjection in offshore environments located at great depths. The technique was first adopted in the pilot project for the Lula field, where we set the global record of the deepest subsea well with gas injection with CO2 at water depths of 2220 meters.
In 2015, we reached the significant milestone of three million tonnes of CO2 separated from natural gas and re-injected into the Santos Basin pre-salt layer, thus preventing its emission to the atmosphere.
At the Lula field pilot project, one of the CO2 injection wells is located at a record water depth of 7,283 ft. In addition to the benefits for the environment, the reinjection of the produced CO2 increases the internal pressure in the reservoir, improving oil recovery.
The technologies we have developed with partners and suppliers demand a set of initiatives that are only possible to undertake with the hard work, planning capacity, and daily commitment of the professionals involved. It is with this spirit of overcoming, and with the pursuit of excellence in our processes that we reach more and more exciting figures.
In the Pre-Salt layer, our output records have been frequent, showing the efficiency of our activities and the achievement of solid results. In 2016, our average annual output operated in the pre-salt cluster was the highest in our history, topping out at 1.02 million barrels of oil per day and surpassing the 2015 volumes by 33 percent.
Thus, at each new challenge, we will continue developing technologies that prove our ability to produce oil continuously and profitably.