The Bureau of Safety and Environmental Enforcement is launching a safety initiative to bring critical information directly to offshore workers on the outer continental shelf. The BSEE!Safe program uses text messages to send links to its published Safety Alerts and Bulletins. The Bureau of Safety and Environmental Enforcement says its final well-control rule removes unnecessary regulatory burdens to responsible offshore development while maintaining safety and environmental protection. The Bureau of Safety and Environmental Enforcement says its staffing and inspections are up, while the environmental group Oceana says that oil and gas drillers have a financial incentive to ignore safety. Ahead of the release of the Trump administration's changes to Obama-era rules governing offshore oil platforms, Michael Bromwich said he is worried.
Regulators say the blowout that killed five workers on a Patterson-UTI rig in Oklahoma was the product of a slow-moving series of missed signals, misleading testing, and miscalculations that failed to control a natural gas influx. The new well control rule is evidence that memories of the Macondo blowout remain a powerful force for caution. Despite the rhetoric on both sides of this hot-button issue suggesting big changes, the final changes were incremental. Nonaqueous drilling fluids, such as synthetic-based and oil-based mud (SBM and OBM, respectively), are used frequently to drill one or more sections of a well to reduce drilling problems such as shale sloughing, wellbore stability, and stuck pipe. Three onshore fields in the Emirate of Sharjah, United Arab Emirates, have more than 30 years of production history from more than 50 gas-condensate wells.
A critical support role within the upstream sector is played by the thousands who work in HSE and sustainability. The HSE performance of the industry has improved dramatically over the decades because of technological advances and a greater understanding of systems, processes, and human performance. Researchers mapped 251 faults in the North Texas home of the Barnett Shale, the birthplace of the shale revolution, finding that wastewater injection there “significantly increases the likelihood for faults to slip.” The new well control rule is evidence that memories of the Macondo blowout remain a powerful force for caution. Despite the rhetoric on both sides of this hot-button issue suggesting big changes, the final changes were incremental.
Australia’s BHP Billiton and the recently acquired Anadarko Petroleum submitted the largest dollar totals of high bids in US Gulf of Mexico Lease Sale 253. Operator Talos Energy now believes Zama’s gross recoverable resource lies in the upper half of its pre-appraisal estimate of 400–800 million BOE. The consortium is working toward a 2020 final investment decision on the project. The deal consists of stakes in nine shallow-water producing fields covering 108,000 gross acres in 10–50 m of water. The new well control rule is evidence that memories of the Macondo blowout remain a powerful force for caution.
Understanding the principles of fluid flow through the production system is important in estimating the performance of individual wells and optimizing well and reservoir productivity. In the most general sense, the production system is the system that transports reservoir fluids from the subsurface reservoir to the surface, processes and treats the fluids, and prepares the fluids for storage and transfer to a purchaser. Figure 1--Production System and associated pressure losses. The reservoir is the source of fluids for the production system. It is the porous, permeable media in which the reservoir fluids are stored and through which the fluids will flow to the wellbore.
For a low-pressure well with solids and/or heavy oil at a depth of less than approximately 6,000 ft and if the well temperature is not high (75 to 150 F typical, approximately 250 F or higher maximum), a PCP should be evaluated. Even if problems do not exist, a PCP might be a good choice to take advantage of its good power efficiency. If the application is offshore, or if pulling the well is very expensive and the well is most likely deviated, ESPCP should be considered so that rod/tubing wear is not excessive. There is an ESPCP option that allows wire lining out a failed pump from the well while leaving the seal section, gearbox, motor, and cable installed for continued use.
A workflow is presented which places far greater emphasis on formation lithology than is usually employed during pore pressure and geomechanical studies. Advanced classification techniques are linked with conventional pore pressure prediction and geomechanical modelling methods to implement the new workflow. The lithological classifications which are developed permit more robust predictions by facilitating the constraint of pore pressure and geomechanical results to available well data. Lithological assignments are developed from well logs using a Bayesian-based multivariate clustering analysis technique which yields a probabilistic Electroclass at each depth along the wellbore. The probabilistic results are analysed with an Expert System that automatically assigns a Lithology to the Electroclass at each depth. The Expert System can be modified for different regions and adjusted (and overruled) by an experienced analyst. The resulting multivariate model, with probabilistic lithological assignment, is used to QC, and if necessary predict, well log curves in missing intervals along the wellbore. Thus, interval velocities across the complete well profile from surface to total depth can be established from well log sonic data. These lithology-dependent velocities are then used to develop pore pressure predictions using an effective stress method in which the governing parameters are themselves lithologically dependent. Likewise, geomechanical properties such as Poisson's Ratio, Young's Modulus, Brittleness Index, and the minimum horizontal stress are calculated using Lithology-dependent parameters. An example is presented for an onshore US unconventional formation in which multiple wells are used to develop a robust lithological classification. The developed lithology then controls the wireline log curve predictions and ultimately the pore pressure and geomechanical predictions in selected wells. The impact of different lithologies on pore pressure and geomechanical estimates can be clearly seen and the impact of parameter setting ascertained for each. It is concluded that predictions of pore pressure and geomechanical properties are considerably enhanced by the far better understanding and consistent inclusion of lithology.
Pathak, Varun (Computer Modelling Group Ltd.) | Hamedi, Yousef (Computer Modelling Group Ltd.) | Martinez, Oscar (Computer Modelling Group Ltd.) | Vermeulen, Stephen (Computer Modelling Group Ltd.) | Kumar, Anjani (Computer Modelling Group Ltd.)
Integrated production systems models are very valuable for predicting the performance of complex systems containing multiple reservoirs and networks. In addition, the value of quantifying uncertainty in reservoirs and production systems is immense as it can build confidence in operational investments. However, traditionally it has been extremely tedious to incorporate uncertainty assessments in the context of integrated production systems modelling. This has been addressed in the current work with the help of a case study.
In the current work, a complex integrated production systems model is presented - from Pre-Salt carbonates reservoir offshore of Brazil. The model includes multiple reservoirs with unique fluid types and complex fluid blending in the production network, multiphase and thermal effects in flowlines and risers, gas separation, gas processing, gas compression, and re-injection for either pressure maintenance or for miscible EOR.
The operational strategies, well placement, and well and network configurations are often based on a single geological realization. With the case study presented in this paper, an integrated way of quantifying geological uncertainty has been presented. A new multi-user, multi-disciplinary tool was used for this study that removed any discontinuities and inconsistencies that typically occur in such projects when multiple standalone tools are used for individual tasks. When quantifying uncertainty on production, the dependence on a single realization was eliminated as uncertain parameters were identified and used for creating robust probabilistic forecasts. Probability distribution curves were generated to represent the uncertainty in overall production from this asset, and the risk associated with operational investments was minimized.
Typically, an end-to-end uncertainty assessment is missing from the traditional Integrated Modelling workflows. With this new approach, the challenge of achieving a truly integrated uncertainty assessment for integrated reservoir and production models has been addressed successfully.
Da Silva de Aguiar, Janaina Izabel (Clariant) | Pimentel Porto Mazzeo, Cláudia (Clariant) | Garan, Ron (Clariant) | Punase, Abhishek (Clariant) | Razavi, Syed (Clariant) | Mahmoudkhani, Amir (Clariant)
Recent studies revealed that solids from lab-generated deposits often exhibit compositional differences from those of field deposits, pointing to a more complex fouling process in field operations. The objective of this work was to understand and apply knowledge from field deposit characteristics in order to design and conduct laboratory experiments which yield solid deposits with comparable compositional fingerprints. This approach allows a more objective and reliable product development and recommendation strategy to be adopted for increased success in the field applications. First, oil and deposit samples from an offshore field was characterized. Second, samples of the asphaltenes extracted from oil (AEO) and from the deposit (AED) were characterized based on solubility using an Accelerated Solubility Test (AST). A customized Asphaltene Dynamic Deposition Loop (ADDL) was used in this study to simulate the precipitation and deposition of asphaltenes from the crude oil. Crude oil used in the tests was from the same well where the deposits were collected. ADDL tests were conducted at high temperature and pressure and the composition of the collected deposit from this test was compared with the deposits from the field. At last, Light Scattering Technique (LST) was applied to screen asphaltene inhibitors (AI). Four candidate chemistries were tested on LST. To confirm the efficiency, the high performer was tested on ADDL under dynamic conditions. Deposits collected from the ADDL were characterized and results showed a high degree of similarity to the field deposit. AI1 was evaluated by ADDL and it decreased the deposition in the filters by 60% and 84% at 1000 ppm. This product was selected to be tested in the field and a plant trial is ongoing.