Marine Technology Reporter Blogs

Brazil’s National Operator, Petrobras has been experimenting with advanced Water-Alternating-Gas injection in a number of offshore plays and recently at the Rio O&G 2014, Petrobras’ Pre-salt manager confirmed that the super-major will be using the technology at most, if not all of its pre-salt plays. The WAG injection process aims to recover more oil from a reservoir and also to recover oil more efficiently. The technology was originally intended to improve sweep efficiency during gas flooding, with intermittent slugs of water and gas designed by and large to follow the same route through the reservoir. Variants include injecting gas as a supplement to water or vice versa, primarily to reach other parts of the reservoir.

The definition of MPD recently adopted by the IADC Underbalanced Operations and Managed Pressure Committee states that: “Managed Pressure Drilling (MPD) is an adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore. According to drilling specialists, bottomhole pressure is normally maintained above pore pressure by controlling the density of the drilling fluid. When density gets too high, the formation begins to absorb the fluid and the fluid density needs to be adjusted. Casing must be run to isolate the open hole before drilling can continue. The common objective of all currently known managed pressure drilling techniques is to stretch or eliminate casing points to allow drilling beyond conventional limits of depth or pressure variation.

As a world leader in construction and remote operations in deep waters, Petrobras has been developing new technologies and testing them with their partners in Brazil’s deepwater pre-salt fields for over a decade. Petrobras has historically opted for an incremental strategy to develop its technological capabilities to explore the Brazil’s offshore oil resources. As deepwater discoveries began to enter the production phase, Petrobras opted for using and FPSOs and wet x-mas trees. These discoveries of supergiant oil fields in the Brazilian pre-salt have offered Petrobras an opportunity for reviewing its technological path and it is becoming clear that the national operator has been increasingly inclined to move as much of the oil production systems to the seafloor as possible…

Today, much emphasis is given to working with real-time production data, real-time pipeline monitoring, leak detection and equipment condition monitoring. ROV/ AUV operations are used to support all sorts of deepwater seafloor construction processes, allowing operators to continuously monitor their subsea systems and intervene when necessary. Basically all equipment being installed on the seafloor has real-time communication systems, which allow operators on the surface to monitor the equipment’s performance and even control much of the equipment from the surface. Equipment that can be monitored from the surface but which cannot be manipulated remotely…

With the experience Petrobras has gained in deepwater field construction, the national operator has learned the best ways to get the job done and who to work with. Much of Petrobras’ deepwater seafloor construction work has been done by DOF, Technip, Subsea 7, FMC and Aker. Large deepwater post-salt fields such as Roncador, Frade and Marlim amongst others have been the main testing grounds of many construction techniques and much of the equipment being installed. Obviously, experience in deepwater seafloor construction has also been gained by Petrobras and service providers in locations such as the GoM and West Africa. Most of the pre-salt subsea trees will be built and installed by FMC, OneSubsea and Aker. FMC has a total order worth $1,5 billion, which was announced in March of 2012.

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.

In any given subsea field there is a multitude of equipment, that need to be constantly monitored. Subsea Multi-Domain Condition Monitoring can be achieved by introducing additional hydrophones, specially designed for detecting sound from rotating machinery, subsea processing equipment, structural integrity, fluid flow rate variations among others. The latest high-end sensor systems ally acoustic condition monitoring with acoustic leak detection. This works in much the same way as surface-based acoustic emission monitoring and can be used to monitor rotating machinery to check speed tracking and resonant frequencies. It can also monitor rotational equipment in subsea plant such as bearing damage, unbalanced pumps, mechanical breakdown and reduced efficiency.

As more and more equipment is placed on the seafloor, especially in deep waters but also in shallow waters, concerns grow over potential hydrocarbon leaks from trees, manifolds, pumps, pipelines, flowlines, risers and valves. It’s no small challenge to have a reliable subsea leak detection system that can monitor the large array of subsea systems used in modern deepwater fields and on top of that there is the need to monitor the working condition of all this equipment and others, such as ESP’s and other pumps, which are rotating equipment. Acoustic emissions are the stress waves produced by the sudden internal stress redistribution of materials caused by changes in the internal structure.

During the recent Rio O&G 2014 Expo and Conference a range of new products for the O&G industry were launched. The size of the event, with over 1,000 companies present and tens of thousands of daily visitors made it a great medium for showing new products to the market. GE had its large booth constantly full and was probably the company, which had the largest number of new products on display. Naxys joined GE in September 2012 as a world-class sensors developer for the subsea sector. With its headquarter in Bergen, Norway, Naxys develops and supplies leak detection and condition monitoring sensors based on proprietary, passive acoustic hydrophone technology.

The last day of the Rio O&G conference began with an early morning presentation on the possible uses of Nanotechnology for O&G exploration and advanced oil recovery. The sector, with the support of IBP (Brazilian Petroleum Institute) has been working on a Nano Agent capable of increasing the average oil recovery by 20%. According to Rustom Mody, Vice-Presidente of Technology at Baker Hughes, presently 60% of nanotechnology patents are from the U.S. and Canada and the number of patents has greatly increased in the last 10 years, with the market experiencing a major growth since 2009. The market presently involves values of over US$ 9 billion, up from the US$ 4,5 billion of 5 years ago.

The latest edition of the Rio O&G 2014 Expo and Conference is easily the biggest installment ever of the largest O&G event in Latin America. Many foreign participants were saying that it was the one of biggest even they’ve seen anywhere and also one of the most well organized. Praises were also lavishly handed out to the quality of the technical presentations, lectures, panels and digital poster sessions. Important developments for the industry have also been announced during the event, such as the news that Brazil’s thirteenth bidding round will take place in the first semester of 2015 and Shell’s Executive Vice President Mark Shuster’s much commented speech…

The Block III Virginia-class Attack Submarines are the most modern subs ever built. They are fast, silent and packed with state of the art technology. The Virginia-class submarines weigh 7,800 tons and are 377 feet long, with a 34-foot beam, they can reach speeds of more than 25 knots submerged. Of the many systems and sensors on board, one of the highlights is the novel Photonics mast system. Electro-optics engineers at Kollmorgen Electro-Optical and its Italian subsidiary, Calzoni have developed the AN/BVS-1 photonics mast system, which is a non-hull penetrating electronic imaging subsystem with visible light camera, infrared camera, and electronic support measures sensors, as well as stealth features that will provide new capabilities for attack submarines.

CTD stands for conductivity, temperature, and depth, and refers to a package of electronic instruments that measure these properties. A device called CTD Rosette is lowered into the water and down to the seafloor to measure the salinity, temperature, depth and concentration of particles in the water column. A CTD device’s primary function is to detect how the conductivity and temperature of the water column changes relative to depth. Conductivity is a measure of how well a solution conducts electricity. Conductivity is directly related to salinity, which is the concentration of salt and other inorganic compounds in seawater. Salinity is one of the most basic measurements used by ocean scientists.

Well Control specialists face serious challenges when dealing with extreme HPHT wells, where pressures may exceed 20,000 psi. Narrow safe operating “windows”, where drilling personnel must remain adequately informed and aware of downhole conditions to ensure early kick detection and response.In this case the wider the safe operating window is the easier it is to assure well control safety. High wellbore temperatures, where normally very high-pressure formations are also typically very hot formations. Reductions in downhole tool reliability will increase dependence on real-time modeling when evaluating and monitoring of downhole conditions.

Helix Energy Solutions has a different concept for using an ROV in conjunction with a subsea coring and sampling rig. Helix’s system, the ROVdrill Mk. 2 actually places the ROV and the rig together inside a cage. Both the Forum Rovdrill and Helix’s ROVdrill MK. 2 are capable of deepwater operations and have their advantages and disadvantages. In this post we’ll take a look at the Helix ROVdrill MK. 2 capabilities. Helix Energy Solutions Group, Inc.’s robotics subsidiary, Canyon Offshore Limited (U.K.), which has an extensive fleet of proven trenching equipment and ROVs, also commercializes the ROVdrill Mk.2 systems. Canyon Offshore’s…

Compact remote methods of seabed geotechnical drilling, coring and sampling are being developed for deepwater operations and at the forefront of lightweight remote Geothechnical drilling are ROV systems combined to small drilling systems. Two companies, Forum Energy Technologies and Helix Energy Solutions, are leading the way in this technology. Forum Energy Technologies has been successfully employing its Rovdrill™ 3 system worldwide. This is Forum’s third generation Rovdrill system and it is where we will begin to look at the intricacies of these remote subsea coring and sampling systems. The advantages of taking the coring/sampling rig to the seabed are obvious, both from a technical and economic standpoint.

Deepwater flow assurance should always be considered from an integrated standpoint, taking into account the well, reservoir, and production angles to make sure the full range of fluid scenarios and compositions are examined, and to avoid costly resampling and re-evaluation after systems are built. Production fluids interact with the reservoir, well, pipeline, surface facilities, and the environment. All these impact flow assurance, leading to potential issues with hydrates, wax, asphaltenes, scales, slugging, emulsion, foam, sand, and corrosion. Deepwater flow assurance requires a full understanding of these interactions and a multi-disciplinary approach to managing them. Modern simulation software allows such an approach to be integrated efficiently into asset team workflows.

With the imminent the start of the next phase of the search for Malaysia Airlines flight MH370, which is likely to get under way towards the end of September, it is interesting to take a look at the vessels and systems which will be participating, as it promises to be a very challenging search due to the harsh weather common to the area and a complex seafloor. Detailed information is being gathered on the topography of the ocean floor west of Australia, which confirms the seabed in some locations to be extremely rugged. This key survey, of a largely uncharted deepwater seafloor, will guide a millimetric search using towed side-scan sonars, magnetometers, sub-bottom profiler and AUVs. The Australian authorities have warned that the search could take a year to complete.

Well stimulation is a well intervention performed on an O & G well to increase production by improving the flow of hydrocarbons from the drainage area into the well bore. The assortment of drilling fluid pumped down the well during drilling and completion can often cause damage to the surrounding formation by entering the reservoir rock and blocking the pore throats (the channels in the rock throughout which the reservoir fluids flow). Similarly, the act of perforating can have a similar effect by jetting debris into the perforation channels. Both these situations reduce the permeability in the near well bore area and so reduce the flow of fluids into the well bore. A simple and safe solution is to pump diluted acid mixtures from surface into the well to dissolve the offending material.

Flow assurance is a relatively new term in oil and gas industry. It refers to ensuring successful and economical flow of hydrocarbons from reservoir to the point of sale and is closely linked to multiphase flow technology. Flow Assurance developed because traditional approaches were inappropriate for deepwater production due to extreme distances, depths, temperatures or economic constraints. The term “Flow Assurance” was first used by Petrobras in the early 1990s (Garantia do Escoamento in Portuguese), meaning literally Guarantee of Flow, or Flow Assurance. Flow assurance is an extremely diverse subject, encompassing many specialized engineering disciplines.