Tight Reservoir Properties Derived by Nuclear Magnetic Resonance, Mercury Porosimetry and Computed Microtomography Laboratory Techniques. Case Study of Palaeozoic Clastic Rocks

Abstract

Backgrand. Lateralized periodic discharges (LPDs) are infrequent electroencephalograph (EEG) findings, and may present in ictal or interictal form. They are regarded as potential electrophysiologic signs of convulsive or nonconvulsive status epilepticus (NCSE). We report four patients who presented with NCSE and one who presented with convulsive status epilepticus in the postictal period, characterized by LPDs in EEG recordings in the first year after stroke. Material and methods. We prospectively evaluated patients who clinically presented with status epilepticus associated LPDs between March 2014 and March 2015. We investigated patients that presented with a new stroke occurrence. We excluded the other LPD etiologies. EEG studies of five patients (two men) who were admitted to our emergency unit with confusion, three of whom had visual symptoms; four were treated for NCSE as diagnosed with LPDs. The fifth patient had convulsive status epilepticus with LPD in the postictal period. Results and Discussion. None of the five patients, who were aged between 68 and 92 years, showed any etiologic factor other than a history of cerebrovascular disease (CVD). Magnetic resonance imaging studies of the patients revealed old infarcts and transitional diffusion restrictions. The clinical and EEG findings decreased substantially upon antiepileptic drug treatment. Herein, we illustrate the first patient who had confusion, visual hallucinations, and ictal and interictal LPD in her consecutive EEGs. Conclusions. CVDs may pave the way for LPDs in patients with a history of stroke because CVDs cause structural brain damage. Patients who present with a similar clinical profile and imaging signs of stroke should be checked for NCSE, particularly in the presence of LPDs in EEGs.

Estimation of absolute permeability using artificial neural networks (multilayer perceptrons) based on well logs and laboratory data from Silurian and Ordovician deposits in SE Poland

“…The analysis covered the Silurian and Ordovician shale and mudstone formations, which are potential unconventional shale gas deposits. These formations are characterized by poor reservoir properties, in particular low permeability (Krakowska and Puskarczyk 2015). Due to the location of the wells within various geological regions, analogous formations are buried at various depths.…”

Computed X-ray microtomography as the useful tool in petrophysics: A case study of tight carbonates Modryn formation from Poland

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Detailed parametrization of the pore space in tight clastic rocks from Poland based on laboratory measurement results

“…Still, it is many to research regarding the tight, gas-bearing formations, which are the object of the interest of petroleum industry (Josh et al 2012;Guo et al 2015;Verri et al 2017). Hence, computed X-ray nanotomography is a valuable laboratory method for the qualitative and quantitative analysis of complicated pore structures and permeability estimation (Cnudde and Boone 2013;Mostaghimi et al 2013;Krakowska and Puskarczyk 2015;Sun et al 2017).…”