MODELLING OF THE FULL ENVELOPE OF CAPILLARY PRESSURE CURVES FROM THE CENTRIFUGE

ABSTRACT The full envelope of capillary pressure curves consists of primary drainage; the bounding loops of spontaneous and forced imbibition; spontaneous drainage and secondary drainage; and scanning loops in between. The capillary pressure curve for primary drainage and forced imbibition may routinely be determined by a high-speed centrifuge and well-known interpretation methods. However, even a shift to an inverted bucket for forced imbibition destroys the reversible, natural fluid displacement process and may create artificial, discontinous step changes in the equilibrium condition of the core. For the spontaneous imbibition branch of the capillary pressure curve, the measurement procedures and their interpretation may still be categorized as being in a development phase. In this paper it is demonstrated how a validated capillary pressure correlation for mixed-wet rock and an associated hysteresis scheme may provide any natural bounding and scanning loop. With the Free Water Level (FWL) always inside the core, a complete capillary pressure envelope may be generated without demounting the core, simply by stepwise increasing and/or decreasing the centrifuge frequency, while recording the FWL level by a capacitance technique. At each point along the core, a saturation reversal process (e.g. from drainage to imbibition), will follow an individual scanning curve. For each frequency, the saturations along the scanning curves are calculated by the hysteresis scheme, and they define the FWL. The positive capillary pressure curve is important to estimate transition zones in the reservoir and to model spontaneous imbibition in a fractured reservoir. The procedure explained in the present paper for a core in a centrifugal field is equivalent to the modelling of contact movement and transition zones in the gravitational field in the reservoir, as previously published in various papers

Finding Data Should be Easier than Finding Oil

The competitiveness of modern enterprises heavily depends on their ability to make the right business decisions by relying on efficient and timely analysis of the right business critical data. In large and data intensive companies such as Equinor, a Norwegian multinational oil and gas company with more than 20,000 employees, gathering such data is not a trivial task due to the growing size and complexity of corporate information sources. As a result, the data gathering task is often the most time-consuming part of the decision making process, in particular when it comes to the work processes of Equinor's exploration geologists that should find in a timely manner new exploitable accumulations of oil or gas in given areas by analysing data about these areas. In this work we present our experience in addressing this data challenge tast at Equinor. We have developed and deployed at Equinor a semantic data access system that relies on the Ontology Based Data Access (OBDA) approach. Our system is based on our solid theoretical contributions and has been extensively evaluated at Equinor

Ontology Based Data Access in Statoil

Ontology Based Data Access (OBDA) is a prominent approach to query databases which uses an ontology to expose data in a conceptually clear manner by abstracting away from the technical schema-level details of the underlying data. The ontology is ‘connected’ to the data via mappings that allow to automatically translate queries posed over the ontology into data-level queries that can be executed by the underlying database management system. Despite a lot of attention from the research community, there are still few instances of real world industrial use of OBDA systems. In this work we present data access challenges in the data-intensive petroleum company Statoil and our experience in addressing these challenges with OBDA technology. In particular, we have developed a deployment module to create ontologies and mappings from relational databases in a semi-automatic fashion; a query processing module to perform and optimise the process of translating ontological queries into data queries and their execution over either a single DB of federated DBs; and a query formulation module to support query construction for engineers with a limited IT background. Our modules have been integrated in one OBDA system, deployed at Statoil, integrated with Statoil’s infrastructure, and evaluated with Statoil’s engineers and data

Footprints of spontaneous fluid redistribution on capillary pressure in porous rock

Pore-scale imaging of two-phase flow in porous media shows that pore filling occurs as cooperative events with accompanying spontaneous fluid redistribution in other parts of the pore space. We present a level set method that controls saturation quasi-statically to model experiments controlled by low, constant flow rates and demonstrate that our method can describe the observed displacement mechanisms. The level set approach determines states of capillary equilibrium, which generally are different for displacement protocols constrained by saturation and pressure. Saturation-controlled simulations of drainage in sandstone show spontaneous fluid redistributions with abrupt pressure jumps and cooperative behavior, including snap-off and interface retraction events, consistent with experimental observations. Drainage capillary pressure curves are lower when saturation, rather than pressure, controls displacement. Remarkably, these effects are less significant for imbibition processes where the development of hydraulically connected wetting phase moderates the cooperative behavior and associated pressure jumps.publishedVersio

Fibroblasts Express Immune Relevant Genes and Are Important Sentinel Cells during Tissue Damage in Rainbow Trout (Oncorhynchus mykiss)

Fibroblasts have shown to be an immune competent cell type in mammals. However, little is known about the immunological functions of this cell-type in lower vertebrates. A rainbow trout hypodermal fibroblast cell-line (RTHDF) was shown to be responsive to PAMPs and DAMPs after stimulation with LPS from E. coli, supernatant and debris from sonicated RTHDF cells. LPS was overall the strongest inducer of IL-1β, IL-8, IL-10, TLR-3 and TLR-9. IL-1β and IL-8 were already highly up regulated after 1 hour of LPS stimulation. Supernatant stimuli significantly increased the expression of IL-1β, TLR-3 and TLR-9, whereas the debris stimuli only increased expression of IL-1β. Consequently, an in vivo experiment was further set up. By mechanically damaging the muscle tissue of rainbow trout, it was shown that fibroblasts in the muscle tissue of rainbow trout contribute to electing a highly local inflammatory response following tissue injury. The damaged muscle tissue showed a strong increase in the expression of the immune genes IL-1β, IL-8 and TGF-β already 4 hours post injury at the site of injury while the expression in non-damaged muscle tissue was not influenced. A weaker, but significant response was also seen for TLR-9 and TLR-22. Rainbow trout fibroblasts were found to be highly immune competent with a significant ability to express cytokines and immune receptors. Thus fish fibroblasts are believed to contribute significantly to local inflammatory reactions in concert with the traditional immune cells

In-between spaces and social interaction: a morphological analysis of Izmir using space syntax

This research tackles the intermediate spaces between buildings and the street, by examining the definition and importance of spatial configuration in relation to urban morphology and social relations. It also analyses how the organisation of in-between space affects social interaction in different urban forms. To understand the complex relations and socio-spatial structure of the city, it is important to use mixed methods. This research utilises various methods to focus on three dissimilar urban morphologies in Izmir, Turkey. Two inner city quarters and one modern housing estate of middle- and high-income groups are compared using space syntax analysis and snapshot observations. These neighbourhoods are selected according to their syntax measures from more integrated to segregated neighbourhoods in the axial analysis. And for a detailed zoomed-in analysis, similar diameter areas are covered for observations. Subsequently, activity patterns are observed at different times of the day, one weekday and one Sunday in three cases. In each neighbourhood, syntactic measures of all selected streets are correlated with these recorded activities. This study reveals that connectivity of streets is important for supplying niches that trigger long-duration activities and social interaction. In modern estates, stationary activities are not correlated strong enough with movement as it is in inner city neighbourhoods. Additionally, in-between spaces increase the frequency of social interaction and co-presence of people particularly in more integrated areas. However, this is only one element in developing sense of community. Further research is needed especially in correlating space syntax with environmental issues, as well as people’s behaviour

Generating Executable Mappings from RDF Data Cube Data Structure Definitions

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