In this work, the authors developed a numerical model of in-situ upgrading (IU) on the basis of laboratory experiences and validated results, applying the model to an IU test published in the literature. This paper outlines the value of 4D for reducing uncertainty in the range of history-matched models and improving the production forecast. The struggle to overcome the challenge of frac hits has led to a critical dialogue about which pathway the shale sector should take. One idea is to simply put the problem at the center of every major decision. If the shale sector’s most complex problem can be solved, it will require companies to use their wells as a team.
JPT Technology Minute Poll: To Which of the Top Five UN Sustainability Development Goals Do You Think the Oil and Gas Industry Will Contribute the Most? Flaring and emissions challenges have recently made news headlines around the world. The goal of this article is to engage you with this important topic by presenting a selection of recent SPE papers which address these challenges through various approaches. Operators face a dilemma in balancing the need for mud weight (MW) to remain below the fracture gradient to avoid losses, while also providing sufficient density to block influxes into the well. JPT Technology Minute Poll: Which Technology Would You Choose for Offshore Compression?
Africa (Sub-Sahara) Tullow's Cheptuket-1 well in Block 12A of northern Kenya has encountered good oil shows over an almost 2,300‑ft interval, the company reported. The first well to test the Kerio Valley Basin, Cheptuket-1 was drilled to a final depth of 10,114 ft. The results indicate the presence of an active petroleum system with significant oil generation, the company said. Post-well analysis now under way will affect future basin exploration decisions. Tullow is the block operator with a 40% interest. Delonex Energy (40%) and Africa Oil (20%) are the other participants.
Africa (Sub-Sahara) Eni successfully completed a new production well in the Vandumbu field, 350 km northwest of Luanda and 130 km west of Soyo, in the West Hub of Block 15/06 offshore Angola. The VAN-102 well is being produced through the N'Goma FPSO and achieved initial production of 13,000 BOED. Production from this well and another well in the Mpungi field will bring Block 15/06 output to 170,000 BOED. Anglo African Oil & Gas encountered oil at the TLP-103C well at its Tilapia license offshore the Republic of Congo. The well intersected the targeted Djeno horizon, and wireline logging confirmed the presence of a 12-m oil column in the Djeno. Total started production from the ultra-deepwater Egina field in approximately 1600 m of water 150 km off the coast of Nigeria. At plateau, the field will produce 200,000 B/D.
Harstad is not the end of the world but you can see it from there, a real frontier area. From this area above the polar circle exploration and development has been lead in the Norwegian and the Barents seas. Exploration wells are being drilled in the now opened former disputed areas, was it worth the fuss? "Technology forum about the Arctic in the Arctic" has always been the slogan of the SPE Northern Norway Workshop. In March 2019, this two-day biannual workshop will raise the stakes, broaden the scope, and showcase all the latest success in the region.
Tosi, Gianbattista (Eni) | Stensland, Dag (Eni) | Winterton, David (Eni) | Zappalorto, Luigi (Eni) | Wang, Haifeng (Schlumberger) | Dupuis, Christophe (Schlumberger) | Denichou, Jean-Michel (Schlumberger) | Horstmann, Mathias (Schlumberger)
Goliat was the first oil discovery in the Barents Sea and holds 174 million barrels of recoverable oil. It is operated by Eni Norge (65% share, with Statoil holding the rest of the equity). Finding oil is important, but safely and efficiently developing it is critical. The remoteness of these frontier projects amplifies the consequences of any delays or issues. Risk prevention and mitigation is the object of particular attention in this new frontier area. Landing the first producer was a particularly sensitive operation, requiring a safe stop a few meters above the top of the reservoir to reduce the risk of landing the section within the reservoir gas cap bearing sandstone.
A geometrical landing would be limited by a depth uncertainty of more than 10 m true vertical depth (TVD): relying on surface seismic information is subject to seismic time-to-depth conversion and the inherent limited resolution of seismic data. Taking these uncertainties into account normally requires setting the casing long in advance of the reservoir top, giving way to a much longer portion of the reservoir section exposed to the overburden shales, with consequent 8 ½’’well bore instability issues and risk of plugging the completion screens.
For the Goliat well, the operator adopted a different approach to land the objective while preventing the risks of setting casing too soon or too late. A new ambitious objective was set: stopping and casing as close as possible to the reservoir, but no closer than 5 m TVD. This could only be done by using the latest generation of deep directional resistivity (DDR) logging-while-drilling tools in the 12 ¼" section, increasing both the precision and the accuracy of the landing by relying on a direct detection of the reservoir top before drilling into it.
The DDR real-time automatic inversion of the subsurface layering revealed the top of the reservoir from 19 m TVD below the bottom hole assembly, a new record. By tracking the top boundary, even at a steep inclination near 70°, the operator confidently stopped drilling when the bit was 6 m TVD above the top of the reservoir, as planned, safely minimizing the distance to be drilled in shales before intersecting the reservoir. The distance to the reservoir was verified in the next section drilled.
The use of DDR for landing wells accurately either above or just below a top reservoir is now a proven powerful option for drilling programs in which risk prevention is required at the top of the reservoir.
This study implements a multidisciplinary approach to porosity (PHIE), shale volume (Vsh) and sand probability estimation from prestack angle gathers and petrophysical well logs. A rock physics feasibility study revealed the optimum petrofacies discriminating ability of extended elastic impedance (EEI) and PHIE. Multilinear regression analysis is then applied to the output of the simultaneous inversion of seismic data to estimate Vsh and PHIE. Probability distribution functions (PDFs) and
Presentation Date: Monday, October 17, 2016
Start Time: 1:50:00 PM
Presentation Type: ORAL
Berg, Tor E. (Norwegian Marine Technology Research Institute (MARINTEK)) | Selvik, ørjan (Norwegian Marine Technology Research Institute (MARINTEK)) | Rautio, Rune (Akvaplan-niva) | Bambulyak, Alexei (Akvaplan-niva) | Marichev, Andrey (Norwegian University of Science and Technology)
This paper discusses the status and development prospects of Arctic escape, evacuation and rescue (EER) solutions in the Greenland and Barents Seas, and briefly describes two recent maritime rescue operations in Norwegian waters. Successful outcomes of maritime EER operations in Arctic waters depend on a number of factors, including design of escape routes, available means of evacuation, distance to available SAR resources, type of rescue units, early information/detection related to maritime accidents, and metocean and ice conditions. Selected items are discussed below.
European Arctic waters comprise the areas from Eastern Greenland to the Barents Sea. There are some major differences between preferred escape, evacuation and rescue (EER) solutions for Greenland, Iceland, Norway and Russia. This is mainly due to differences in national EER philosophies, organization and availability of search-and-rescue (SAR) resources. In Norwegian waters, the preferred EER solution is based on governmental SAR helicopters, while ships operated and coordinated by state salvage departments are the most important tools for Russian EER at sea. This difference reflects the distinctions between the Norwegian and Russian Arctic waters in terms of distances, infrastructure and conditions. Norway has approximately 20% winter ?? ice cover, while most of Russia’s Arctic waters are covered by ice in winter. Russia's SAR system in the Arctic is based on icebreakers and ice-class salvage vessels.
This paper discusses the current status of and development prospects for Arctic EER solutions for the Greenland and Barents Seas,and briefly describe how successful outcomes of maritime EER operations in Arctic waters depend on a number of factors such as the design of escape routes, available evacuation means, distance to available appropriate SAR resources, early information about and detection of maritime accidents, and metocean and ice conditions. The challenges we discuss include:
- Traffic surveillance and detection of maritime accidents
- Operability of evacuation means under Arctic conditions
- Transit speed for seaborne rescue vehicles
- Transfer of personnel from lifeboat/life rafts to helicopter or rescue vessel.
Peikert, Ulrike (Stefan Wessling –Baker Hughes) | Ritzmann, Nicklas (Stefan Wessling –Baker Hughes) | Larsen, David S. (Stefan Wessling – Baker Hughes) | Rommetveit, Brita (Eni Norge) | Mele, Maurizio (Eni S.P.A) | Galli, Maria Teresa (Eni S.P.A)
Formation evaluation in high-angle / horizontal (HAHz) wells is particularly challenging in complex reservoirs such as channelized sands. Data acquired in such con-text cannot be fully representative of the reservoir phys-ical properties if the reservoir architecture is not proper-ly considered in forward modeling and inversion.
This paper presents a case study from a channelized sand reservoir where a combined interpretation of LWD images and resistivity inversion delivered corrected formation resistivity values for a water saturation esti-mate. Formation evaluation data from different logging-while-drilling (LWD) tools were used to land a horizon-tal well in the channelized sand reservoir (Barents Sea). The inversion of resistivity data was performed to ob-tain a real-time reservoir model and to support steering decisions. The real-time inversion results were then improved in a post-well analysis using memory data with higher resolution. Inversion intervals with poor data match were re-processed, enabling assessment according to quality control knowledge. An additional benefit from LWD resistivity memory data is that more components are available, facilitating a more substanti-ated evaluation of formation properties. The inversion process includes constraints from image interpretation: formation dips, interpreted from borehole images at best resolution, were used to limit the inversion pa-rameters and improve the underlying earth model for saturation estimates. In a further step, the entire reser-voir architecture was used to constrain the inversion process in structurally complex intervals. Constrained inversion delivered a geologically sound model of the formation resistivity, wherein bedding structures are better resolved when compared to unconstrained inversion.
Post-well analysis of this dataset also includes different inversion options like interval lengths and automation settings. The results of the different approaches will be discussed in detail, including the final resistivity map for parts of the channelized sand reservoir. Analysis of differences between synthetic and measured data and the integration with other well data such as borehole images was utilized to refine the underlying earth mod-el in challenging intervals. The final target was to ob-tain a representative model of the reservoir physical properties, allowing a robust and consistent reservoir characterization.