Finding and starting a new career can be a fairly straightforward process for some or a daunting task for others. The transition may start in the mind when one begins to first foster thoughts about it. A significant change in direction, particularly when it breaks free of the status quo imposed by a peer group, often comes with its share of self-doubt lurking in the corner. However, when one does go through with the career transition, there are often rewarding results, although sometimes not in ways initially envisaged. You will read about how the transitions improved the careers and lives of the individuals, the motivation behind the change, and what had to be sacrificed to see it through. Read on to see how previous experiences help with career transitions, what sorts of resources were invaluable in managing the transition, and the soft skills that were relevant in ensuring that the career transition was a success. I believe that one of my biggest professional transitions, which set me onto my current path, was switching from film and physics studies to petroleum engineering. In 2004, I was attending university in Florida.
Alkhazmi, Bashir (Centre for Enhanced Oil Recovery and CO2 Solutions, Heriot-Watt University) | Farzaneh, S. Amir (Centre for Enhanced Oil Recovery and CO2 Solutions, Heriot-Watt University) | Sohrabi, Mehran (Centre for Enhanced Oil Recovery and CO2 Solutions, Heriot-Watt University) | Buckman, Jim (Centre for Environmental Scanning Electron Microscopy, Heriot-Watt University)
The predictions of the performance of water-alternating-gas injection under near miscible and different wettability conditions using the current commercial reservoir simulators are very difficult and associated with significant uncertainties. Hence, experimental data are needed to tune reservoir simulators and optimize the performance of WAG injection in the field.
A series of coreflood experiments has been carried out, under ultra-low gas/oil interfacial IFT level, on the same sandstone core with three different wettability conditions; water-wet, weakly-water-wet and mixed-wet. In this study, we present the performance of WAG injection, in terms of oil recovery, under near miscible and weakly water-wet conditions in a homogenous sandstone rock and then comparisons of these results with those in water-wet and mixed-wet systems. To minimize the uncertainty that may associate with the experimental results, the same long and large sandstone core (2in × 2ft) was used in all of the coreflood experiments, presented in this paper, as well as the same core preparation and experimental procedure were repeated.
Analysis of the oil recovery profile, for weakly water-wet core, shows that about 62 % (IOIP%) of recovered oil was achieved by the preliminary water flood whereas an amount of 81.5 % (Sorw %) of the remaining oil, after water flood, was recovered by the alternation of water and gas injection cycles. The results of our coreflood experiments show also that the performance of secondary water flood increased as the direction of wettability changes from water-wet to mixed-wet, passing through weakly water-wet conditions. The oil recovery efficiency by different gas injection cycles, under near miscible and three different wettability conditions, increased as further WAG cycles carried out. However, their oil production rates decreased when wettability turns from water-wet towards mixed-wet system. Although the ultimate oil recoveries were 96.7 %, 92 % and 88.5 % (IOIP%) in mixed-wet, weakly-water-wet and water-wet respectively at the end of WAG injections, the overall oil recovery performance, post-waterflooding, was slightly higher in water-wet, then less in weakly water-wet and much lower in mixed-wet system. Comparison of the water and gas injectivity behaviors during near miscible WAG injection revealed that water and gas injectivity values increased when core wettability turns from water-wet towards mixed-wet, passing through weakly water-wet conditions.
Most of the existing three-phase relative permeability correlations were developed for water-wet system and however, they are widely applicable for a non water-wet reservoir. This has increased the uncertainties associated with those three relative permeability values especially for the data obtained for mixed-wet system. Hence, representative and accurate experimental data, for different wettability conditions, are needed to, firstly, obtain a reliable three-phase relative permeability and its hysteresis values, and secondly, to optimize the WAG process using the existing reservoir simulators.
Electric Submersible Pump (ESP) is a key artificial lift technology to the petroleum industry. Worldwide installations of ESPs are in the range of 130,000 units, contributing to about 60% of the total worldwide oil production. An ESP is made up of hundreds of components integrated together to perform the lifting function. Materials in these components belong to several categories including metals, ceramics, polymers, and others. A good understanding of these materials and vigilant selection for a specific application are critical to the reliability and run life of an ESP system. This paper presents an overview of two classes of materials used in ESP systems: metallic and ceramic materials. A subsequent paper is planned to cover all other categories of materials. The intent is to provide a reference for ESP field application engineers who are responsible for ESP design, component selection, equipment longevity and production optimization.
The information compiled in this paper is a result of extensive literature review. It covers materials used in the motor, protector, pump, and cable (Sensor, packer, Y-tool, diverter valve, surface components of variable speed drives and transformer not included). For each class of materials, it identifies relevant material properties and discusses suitable application conditions.
Produced water chemical compositional data are collected from a carbonate reservoir which had been flooded by North Seawater for more than 20 years, so there is an opportunity to analyse the large amount of produced water data collected, understand the brine/brine and brine/rock interactions and explore the impact factors behind them. In some publications, core flood experimental tests were performed with chalk cores or carbonate columns in order to make an understanding of possible chemical reactions occurring triggered by injected water with different composition (Seawater, low salinity water or any other brine). However, most of the time the laboratory conditions where core flooding experiments are implemented cannot fully simulate the real reservoir conditions. Therefore, in this study, with the help of the valuable produced water dataset and some basic reservoir properties, a one-dimensional reactive transport model is developed to identify what in situ reactions were taking place in the carbonate reservoir triggered by seawater injection.
From the perspective of reservoir mineralogy, calcite, as the dominant mineral in the carbonate reservoir, is relatively more chemically reactive than quartz and feldspar which are usually found in sandstone. Whether calcite is initially and dominantly present in the carbonate reservoir rock is dissolved under seawater flooding or not is the first key issue we focused on. The effects of calcite dissolution on the sulphate scaling reactions due to incompatible brine mixing and the potential occurrence of carbonate mineral precipitation induced by calcite dissolution are investigated and discussed in detail. The comparison of simulation results from the isothermal model and the non-isothermal model show the important role of temperature during geochemical processes. The partitioning of CO2 from the hydrocarbon phase into injected brine was considered through calculation of the composition of reacted seawater equilibrated with the CO2 gas phase with fixed partial pressure (equivalent with CO2 content), then subsequently the impact of CO2 interactions on the calcite, dolomite and huntite mineral reactions are studied and explained. We also use calculation results from the model to match the observed field data to demonstrate the possibility of ion exchange occurring in the chalk reservoir.
In the United Kingdom Continental Shelf (UKCS), a significant heavy oil prize of 9 billion barrels has been previously identified, but not fully developed. In the shallow unconsolidated Eocene reservoirs of Quads3 and 9, just under 3 billion barrels lie in the discovered, but undeveloped fields, of Bentley and Bressay. Discovered in the 1970s, they remain undeveloped due to the various technology challenges associated with heavy oil offshore and the presence of a basal aquifer. The Eocene reservoirs represent significant challenges to recovery due to the unconsolidated nature of the hydrocarbon bearing layers. The traditional view has been that such a nature represents a risk to successful recovery due to sand mobility; reservoir and near wellbore compaction; wormhole formation; and injectivity issues.
We propose improving the ultimate oil recovery by a combination of aquifer water production and compaction drive. By interpreting public domain data from well logs, the range of geomechanical properties of Eocene sands have been determined. A novel approach to producing the heavy oil unconsolidated reservoirs of the UKCS is proposed by producing the aquifer via dedicated water producers situated close to the oil-water contact. The location was determined by sensitivity analysis of water producer location and production rates. By locating water producers at the OWC with a production rate of 20,000 bbls/day of fluids, the incremental recovery at the end of simulation is increased by 4.1% OOIP of the total modelrelative to the ‘no aquifer production’, casesuggesting a significant increase in recovery can be achieved by producing the aquifer. A rate of 30,000 bbld/day located at the OWC was found to increase incremental recovery by 5.8 %OOIP relative to the ‘no aquifer case’. In all cases, as the reservoir fluid pressure is reduced, oil recovery increases via compaction and reduced water influx into the oil leg. This reduced pressure leads to a higher tendency towards reservoir compaction which is expressed as a change in mean effective stress and porosity reduction.
A suite of 61 companies ranging from supermajors to small, upstart independents were awarded 123 licenses over 229 blocks or partial blocks in the North Sea in the UK’s 30th Offshore Licensing Round. The round, which primarily involved previously explored or mature areas, promises “to lead very quickly to activity, providing a welcome boost to exploration,” said the UK’s Oil and Gas Authority (OGA). Shell led the way in overall licenses awarded with 12, seven of which the Anglo-Dutch firm will operate.
A suite of 61 companies ranging from supermajors to small, upstart independents were awarded 123 licenses over 229 blocks or partial blocks in the North Sea in the UK’s 30th Offshore Licensing Round. The round, which primarily involved previously explored or mature areas, promises “to lead very quickly to activity, providing a welcome boost to exploration,” said the UK’s Oil and Gas Authority (OGA). Shell led the way in overall licenses awarded with 12, seven of which the Anglo-Dutch firm will operate. It committed to drill two wells and shoot 3D seismic. Equinor, the longstanding Norwegian operator formerly known as Statoil and freshly renamed as of this month, took nine licenses spread across the UK shelf, eight as operator.
A flexible pipe is composed of several layers, each having a specific function (Figure 1). The carcass is a metallic layer designed to withstand external compression forces in the radial direction. The internal pressure sheath is a polymeric layer used to contain the fluid inside the pipe. The pressure armor is a metallic layer designed to withstand the internal pressure. The tensile armors are made of metallic wires designed to resist axial forces acting on the pipe.
Shell has selected the Sevan 400 FPSO concept for redevelopment of Penguins field. The new circular unit will mirror the Western Isles FPSO deployed by Dana Petroleum in the northern North Sea. Royal Dutch Shell is breathing new life into an old basin by greenlighting its first new manned installation in the northern North Sea in almost 3 decades. The Anglo-Dutch firm has made a final investment decision on redevelopment of the Penguins oil and gas field, discovered in 1974 and first developed in 2002. A new floating production, storage, and offloading (FPSO) vessel with a production capacity of 45,000 BOE/D and storage capacity of 400,000 bbl will be tied to eight new wells.