Wyniki wyszukiwania - BazTech

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Determination of stress state based on well logging data and laboratory easurements – a CBM well in the southeastern part of the Upper Silesian Coal Basin (Poland)

Kępiński Michał

Geology, Geophysics and Environment

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2020

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Vol. 46, no. 2

77--92

EN

The main objective of this study is to present calculation methods of horizontal stress profiles, taking into account the stress boundaries model, poro-elastic horizontal strain model and the effective stress ratio approach, using calibration with wellbore failure. The mechanical earth model (MEM) parameters from log measurements and well testing data were estimated for a well located in the southeastern part of the Upper Silesian Coal Basin. Log-derived horizontal stresses of the well are commonly treated as the final product of geomechanical modeling in oil and gas practices. A less popular method for estimating horizontal stresses is based on Kirsch equations juxtaposed with compressional and tensile failure observed on a micro-imager or six-arm caliper. Using this approach, horizontal stresses are determined based on the fact that when hoop stresses exceed the formation’s tensile strength, tensile fractures are created, and when those stresses exceed the compressive strength of the formation, breakouts can be identified. The advantage of this method is that it can be run without in situ stress measurements. The presented workflow is recommended every time there is an image log and dipole sonic measurement in the available dataset, both being necessary to observe the failure zones and MEM.

2

Geomechanical modelling of Paleozoic Shale Gas Formation: a case study from the Baltic Basin, northern Poland

Słota-Valim M., Sowiżdżał K., Jędrzejowska-Tyczkowska H.

Geology, Geophysics and Environment

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2017

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Vol. 43, no. 3

249--269

EN

The article presents the importance and position of geomechanical modelling workflow in reservoir characterization studies dedicated to unconventional shale reservoirs. We show the results of 3D geomechanical modelling carried out in an onshore area within the Baltic Basin, northern Poland, where the Silurian and Ordovician shale formations are the exploration targets. The fundamental elements of the methodology, processes, and available datasets used in the modelling are discussed. The petrophysical, elastic, and mechanic properties of the rock were applied in the modelling process, along with the principal stresses and pore pressure in the geological formation. Moreover, the main calculation methods and data requirements for the Mechanical Earth Model construction are discussed. A comprehensive 3D geomechanical model was constructed, providing important information to engineers and decision makers which allows them to optimize well placement, the direction of the horizontal section of the borehole and the parameters of hydraulic fracturing treatment. The model can identify zones of higher potential within the area of interest in terms of efficient stimulation treatment design.

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Integrating new data acquisition to develop tight gas reservoir of a mature field through multilayer fracture stimulations

Stefanescu D. P., Falk I., Iturbe Y.

AGH Drilling, Oil, Gas

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2015

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Vol. 32, no. 1

153--173

EN

Laslau Mare field is situated in the central part of the Transylvania Basin, in Romania. This is a mature gas field, composed by multi-layered sandstone reservoirs, grouped in six production packages. The permeability of the reservoirs is decreasing with depth, resulting in tight gas formations in the two deepest reservoirs. One of these tight reservoirs presents a high interest for reserves development in order to accelerate the recovery factor of the field. Compared to the other production packages, which have higher recovery factors (~80%), this package has a current RF of only 65%, with more attractive remaining recoverable gas volumes. The reservoir model was built based on 3D seismic and old log data. After history matching and simulation, a remaining gas in place map was created, in order to visualize the areas of interest for future drilling or workover operations. One new infill well was drilled in 2014, in an area with higher remaining gas in place. Special logging and side- wall coring were executed in this well, in order to get a better characterization of the reservoir properties and to build a geomechanical model for hydraulic frac design. The subject package still has a decent reservoir pressure which keeps an acceptable value of the productivity index of the producer wells. The reservoir pressure recorded after the drilling helped to update the static reservoir pressure in the area; the new points were incorporated in the dynamic model in order to get morę control in the pressure history match. New population of static properties such as: porosity, net to gross and permeability have been included in the dynamic model to generate the forecast production profile for the infill well and neighbor wells. The infill is a dual completion well which means the deeper zone produces through the tubing and the shallower zone through the annulus being separated by a packer. These two zones have two different dynamic models. The production forecasts has been done also based on decline curve analysis DCA, using historical production of the neighbor wells as a reference and the decline rate of the area, in each reservoir. In that order of ideas the infill has two gas production forecasts coming from each methodology, to compare with the real gas production, which allows us evaluating the results in the well. Based on the new data, the frac stages were defined and simulated in the deeper tight reservoir, in order to select the best target layers. The initial plan was to do multistage frac stimulation, but the idea was discarded after evaluating the operational feasibility. Ten frac stages have been evaluated creating a local refmement grid around the well and designing a fracture simulation scenario. The results pointed out one stage as being the best in terms of cumulative production and it was chosen as the only finał target for frac. A PLT log was run in the infill well for the purpose of identifying the risk of water layers and the production contribution of the perforation intervals. This was matched very well with the simulation results. The results and experience gained from this new well are helping with the further planning of the production development strategy of this production package in order to inerease the final recovery factor.

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Mechaniczny Model Ziemi. Nowy i konieczny warunek sukcesu w poszukiwaniach i eksploatacji złóż niekonwencjonalnych

Jędrzejowska-Tyczkowska H., Słota-Valim M.

Prace Naukowe Instytutu Nafty i Gazu

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2012

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nr 183

15--26

PL

W dziedzinie poszukiwań węglowodorów, jednym z najbardziej ekscytujących odkryć minionego dziesięciolecia było stwierdzenie występowania znacznych akumulacji (początkowo na kontynencie północnoamerykańskim) szczególnie gazu ziemnego w formacjach łupków bitumicznych, pomijanych dotąd jako skała kolektorska w interpretacji geologicznej. Ogromne powodzenie koncepcji, a w ślad za nią sukces ekonomiczny firm poszukiwawczych i wydobywczych, zdopingował międzynarodową społeczność naftowców do weryfikacji nowych możliwości odkryć w pozostałych częściach świata. Na kontynencie europejskim krajem, w którym potencjalne możliwości występowania gazu w formacjach łupków (przede wszystkim sylurskich i dewońskich) są bardzo duże, jest właśnie Polska. W rozdziale opisującym Mechaniczny Model Ziemi scharakteryzowano niektóre prace związane z rozpoznaniem właściwości mechanicznych ośrodka skalnego. Rozpoznanie nowego typu obiektów złożowych, objętych wspólną nazwą „złóż niekonwencjonalnych", wymaga doskonałej znajomości właściwości mechanicznych ośrodka skalnego. Jest to dziedzina, która w Polsce w bardzo niewielkim stopniu wykroczyła poza obszar badań laboratoryjnych.

EN

Within the past two decades we could witness a particular redirection of research interests and technical realization due to discovery of energetic potential in shale formations, quite different from geological characterization of typical reservoir rocks like sandstones or carbonates. It is stated that the evaluation of the new type of reservoirs called "unconventional oil and gas reservoirs" requires excellent knowledge about mechanical properties of the rock medium. It is a discipline which in Poland only slightly exceeded the laboratory research, especially with reference to prospecting for hydrocarbons. In this paper, basic theoretical information is presented as arguments for application and brief characteristics of selected studies related to examination of rock medium mechanical properties.

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Mechaniczny model Ziemi jako nowy i konieczny warunek sukcesu w poszukiwaniach i eksploatacji niekonwencjonalnych złóż węglowodorów

Jędrzejowska-Tyczkowska H., Słota-Valim M.

Nafta-Gaz

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2012

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R. 68, nr 6

329-340

PL

Obserwowane w skali światowej zainteresowanie potencjałem energetycznym zgromadzonym w formacjach łupkowych, mających odmienną charakterystykę geologiczną i złożową niż rozpoznawane i eksploatowane standardowo złoża w formacjach piaskowcowych i węglanowych, spowodowało częściowe przekierunkowanie zainteresowań badawczych i realizacji technicznych. Stwierdzono, że rozpoznanie tego nowego typu obiektów złożowych, objętych wspólną nazwą "złóż niekonwencjonalnych", wymaga doskonałej znajomości właściwości mechanicznych ośrodka skalnego. Jest to dziedzina, która w Polsce w bardzo niewielkim stopniu, szczególnie w odniesieniu do poszukiwań węglowodorów, wykroczyła poza obszar badań laboratoryjnych. W publikacji przedstawiono podstawowe przesłanki teoretyczne stanowiące argumenty do aplikacji oraz krótko scharakteryzowano niektóre prace związane z rozpoznaniem właściwości mechanicznych ośrodka skalnego.

EN

Within the past two decades we have witnessed a particular refocusing of research interests and technical realization, due to the discovery of the energy potential in shale formation, far different from geological characterization point of view than typical reservoir rocks like sandstones or carbonates. It is stated that the evaluation of the new type of reservoirs so called "unconventional oil and gas reservoirs" require excellent knowledge about mechanical properties of rock medium. It is a discipline, which in Poland to a small extent, especially with reference to prospecting for hydrocarbons, gone beyond laboratory research. In this paper is presented basic theoretical premises as arguments for application and a brief characteristic of selected studies associated with the diagnosis of the mechanical properties rock.