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1

Impact of the capillary pressure-saturation pore-size distribution parameter on geological carbon sequestration estimates

Cheng Ch.-L., Perfect E., Yu T. E., Gragg M. J.

Journal of Sustainable Mining

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2017

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Vol. 16, iss. 3

67--72

EN

Cost estimates for geologic carbon sequestration (GCS) are vital for policy and decision makers evaluating carbon capture and storage strategies. Numerical models are often used in feasibility studies for the different stages of carbon injection and redistribution. Knowledge of the capillary pressure-saturation function for a selected storage rock unit is essential in applications used for simulating multiphase fluid flow and transport. However, the parameters describing these functions (e.g. the van Genuchten m pore size distribution parameter) are often not measured or neglected compared to other physical properties such as porosity and intrinsic permeability. In addition, the use of average instead of point estimates of m for numerical simulations of flow and transport can result in significant errors, especially in the case of coarse-grained sediments and fractured rocks. Such erroneous predictions can pose great risks and challenges to decision-making. We present a comparison of numerical simulation results based on average and point estimates of the van Genuchten m parameter for different porous media. Forward numerical simulations using the STOMP code were employed to illustrate the magnitudes of the differences in carbon sequestration predictions resulting from the use of height-averaged instead of point parameters. The model predictions were converted into cost estimates and the results indicate that varying m values in GCS modeling can cause cost differences of up to hundreds of millions dollars.

2

The influence of wettability on the petrophysical parameters of reservoir rocks

Kułynycz V.

AGH Drilling, Oil, Gas

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2017

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Vol. 34, no. 3

775--785

EN

Knowledge of the reservoir rock wettability and its influence on petrophysical properties is a key factor to determine the mechanisms and assess the efficiency of oil recovery. In the reservoir rock at the presence of different liquids, it is very important to obtain information about the type of wettability of the rock. Since the understanding of the relationship between wettability and distribution of water and oil in the pore space is necessary to assess the efficiency of oil recovery. Wettability is one of the main parameters that determines the position of the liquid in the reservoir pore space and fluid flow. Wettability affects the properties of petrophysical rock containing hydrocarbons, among others, saturation, capillary pressure, relative permeability, electrical properties of reservoir rocks. Also affects the multiphase flow in porous media. The aim of this article is to characterize the petrophysical parameters of rocks dependent wettability, an overview of the research state of the impact of wettability on the selected petrophysical parameters and presents directions of the future research.

3

Predicting relative permeability from experimental capillary pressure porous plate test for two phase flow

Czarnota R., Janiga D., Stopa J., Wojnarowski P.

AGH Drilling, Oil, Gas

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2017

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Vol. 34, no. 2

323--334

EN

Relative permeabilities relationships as a function of fluids saturation are one of the most important parameters for describing multiphase flow processes in reservoir rocks. When direct laboratory tests are not available for investigating oil-water multi-phase flow in rocks, then indirect prediction techniques using relative permeability functions are widely used, e.g. from capillary pressure test. In this study the measurement of capillary pressure was performed on rocks plugs with different characteristics at reservoir conditions using porous plate method. During measurement semi-permeable membrane was used with 15 bar threshold pressure, what allowed to register formation water saturation, at changing differential pressures steps. Desaturation at each pressure stage was continued until no more produced liquid was observed. Water saturation point at maximum capillary pressure applied is assumed to be final irreducible water saturation. Application of porous plate method provides sufficient stabilization time, allowing to achieve uniform saturation distribution. In this research, Brook-Corey model was used to predict relative permeability from experimental measured capillary pressure data for oil-water phase flow in porous media. As a result, it is possible to obtain more accurate capillary pressure outcomes, and relative permeability curves for the two-phase system, than other methods used in practice. Performing capillary pressure measurements at reservoir conditions, allows to restore the processes occurring in the reservoir.

4

Fractional flow formulation for three-phase non-isothermal flow in porous media

Wójcik W., Temirbekov N., Baigereyev D.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 7

24--31

EN

The present paper focuses on the simulation of three-phase non-isothermal compressible flow in porous media taking into account capillary effects. We propose a new formulation of the considered non-isothermal problem in which the gradients of capillary pressure functions are eliminated from the pressure and temperature equations by the introduction of a change of variables for the pressure. The mentioned change of variables is referred to as the global pressure. A computational algorithm for the numerical implementation of the problem using the finite difference method is proposed. A priori estimate for the solution of the difference problem is obtained. The results of numerical experiments on the example of a one-dimensional problem are presented.

PL

W pracy autorzy koncentrują się na symulacji trójfazowego nie izotermicznego ściśliwego przepływu w środowiskach porowatych przy uwzględnieniu efektów kapilarnych. Zaproponowano nowe sformułowanie zagadnienia w którym gradienty funkcji ciśnienia kapilarnego są wyeliminowane z równań ciśnienia i temperatury poprzez zamiane zmiennych dla ciśnienia globalnego. Zaproponowano implementację algorytmu wykorzystując schemat różnicowy. Wyniki obliczeń dla jednowymiarowego zagadnienia przedstawiono w zakończeniu pracy.

5

An evaluation of hydrocarbon deposit tightness in aspect of CO2 sequestration

Blicharski J.

AGH Drilling, Oil, Gas

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2015

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Vol. 32, no. 4

s. 671--682

EN

Depleted hydrocarbon deposits due to large capacity and proven tightness are often considered as prime candidates for CO2 sequestration in geological structures. The tightness of these structures is mainly connected with the existence of water saturated overbunden rocks of very low permeability which form a natural barrier for the migration of hydrocarbons. This paper explains the sealing mechanisms of caprocks resulting from capillary forces at the interface of hydrocarbon – water and carbon dioxide – water contact. Other ways of caprock leakage due to rock fracturing or reactivation of natural faults and fi ssures were also investigated.

6

Krzywa ciśnienia kapilarnego jako miara zdolności odwadniania osadów filtracyjnych

Drobnik R., Składzień J., Szymków J.

Inżynieria i Aparatura Chemiczna

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2009

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Nr 4

30-31

PL

W ramach pracy przeprowadzono szereg prób filtracji i odwadniania materiałów ziarnistych na filtrze próżniowym. Długotrwałe odwadnianie przy zmiennych warunkach procesu pozwołiło na uzyskanie krzywych ciśnienia kapiłarnego. Badania prowadzono dla zmieniających się wartości ciśnienia odwadniania w zakresie od 0,01 MPa do 0.05 MPa oraz dwóch rodzajów odwadnianych cieczy. Materiałem ziarnistym użytym w badaniach była ziemia okrzemkowa (Celite) o gęstości p = 2150 kg/m3 i przeciętnej wielkości ziarna d50 = 54 @mu; Potwierdzono możliwość zastosowania krzywej kapilarnej do oceny zdolności placka fiłtracyjnego do odwadniania.

EN

A number of filtration and dewatering tests were carried out in a labo-ratory vacuum filter. Long-term dewatering of filter eakes with varia-ble process parameters ailowed one to obtain individual capillary pres-sure curves. The study was carried out for dewatering pressure vary-ing in a rangę from 0.01 MPa to 0.05 MPa and using two types of dewa-tered hquid. Granular materiał used in tests was diatomaceous earth (Celite) with density of ρ = 2150 kg/m3 and average particle diameter equal to d50>/sub>= 54 μ. Application of the capiHary pressure curve to est-imate the ability of filter cake for dewatering was confirmed.

7

Wyznaczanie położenia konturów złożowych dla złóż ropy naftowej w oparciu o kryteria hydrodynamiczne, z uwzględnieniem zmiennej gęstości płynów złożowych i ciśnień kapilarnych

Zawisza L.

Wiertnictwo, Nafta, Gaz

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2007

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T. 24, z. 2

955-964

PL

Wielkość i kształt pułapki złożowej wyznaczają granice geologiczne warstw oraz powierzchnia konturu złożowego. Na położenie konturów złożowych mają wpływ ruch przepływających wód złożowych, własności zbiornikowe skał oraz własności płynów złożowych. W pracy przedstawiono oryginalną metodykę kartowania pułapek złożowych dla ropy naftowej. Metodyka ta uwzględnia wpływ zarówno dynamiki wód podziemnych, jak i zmian gęstości płynów złożowych oraz efektu ciśnienia kapilarnego na położenie konturów złożowych. Pozwala ona na wyznaczenie położenia hydrodynamicznych pułapek złożowych w przestrzeni trójwymiarowej, w warunkach przepływających wód oraz dużej zmienności własności skał zbiornikowych i płynów złożowych. Metodyka ta umożliwia wyznaczanie konturów złożowych zarówno w złożach typu masywowego, jak i w złożach typu warstwowego. Realizację opracowanej przez autora metodyki kartowania pułapek złożowych przedstawiono na przykładzie złóż ropy naftowej Pomorsko i Czerwieńsk, występujących w utworach dolomitu głównego, na obszarze przedsudeckim.

EN

The size and magnitude of a reservoir trap are determined by the geologic boundaries of strata and contour of the reservoir. The location of contours is determined by the movement of the fl owing reservoir water, reservoir properties of rocks and properties of reservoir fluids. An original methodics of mapping reservoir traps for oil is presented in the paper. The method employs both the influence of groundwater dynamics and also variability of density of reservoir fluids and the capillary pressure effect on the location of the contours. It enables determining locations of hydrodynamic traps in a 3D space, in the condition of fl owing water and high variability of properties of reservoir rocks and reservoir fluids. The method also enables determining reservoir contours both in the structural and stratigraphic type of reservoir. The realization of the presented method of mapping reservoir traps in presented on the example of oil fields Pomorsko and Czerwieńsk, occurring in the Main Dolomite beds in the Fore-Sudetes area.