SPE Moscow section SPE Moscow section

Mathematical modeling of phase behavior of multicomponent hydrocarbon mixtures is an essential part of up-to-date practices in petroleum reservoir engineering. Phase behavior calculations form the basis of the PVT software, as well as the 'flash' procedures for determination of phase state and compositions within compositional flow simulators. Adequate description of phase behavior is important for simulation of petroleum production with intensive phase transitions in the reservoir, wells and surface facilities.

One of the key assumptions of industry adopted models is that phase state of the hydrocarbon mixture and phase compositions correspond to the condition of thermodynamic equilibrium. However, there are typical cases for oil and gas-condensate reservoirs when field data are principally inconsistent with equilibrium models. Some examples to give are data of well operation at Novogodneye, Vuktylskoye, Krasnoleninskoye, Kamennoye and many other fields.

In hydrocarbon production, non-equilibrium effects are evident in the following cases:

1) pressure increase in a reservoir (by water or gas injection) following previous pressure depletion with evaluation of the second hydrocarbon phase (liberation of dissolved gas from oil or retrograde condensation in a gas-condensate system) – so-called gas dissolution / condensate evaporation hysteresis;

2) pressure depletion in a gas-condensate reservoir below the maximum condensation pressure (transition from retrograde condensation to direct re-vaporization);

3) gas injection in oil or gas-condensate reservoir.

Similar processes may also take place during hydrocarbon flow in wellbores and surface facilities.

Non-equilibrium effects result in considerable (tens or hundreds percent) deviation of actual reservoir system parameters (saturation pressure, production composition) from their estimates by equilibrium models.

For practical needs, reservoir engineers are limited to either using equilibrium compositional models with no account for non-equilibrium effects, or black oil models with the option of limited gas dissolution /condensate vaporization/ This option is based on a simple technical relation and doesn't consider specific physics of non-equilibrium processes.

In the presentation, methods and algorithms are presented for non-equilibrium phase behavior simulations suitable for wide practical use. A relation is shown between non-equilibrium effects and simulation scale. As the applications, flow simulations with compositional and black oil formulations are considered. Phase behavior simulation cases are shown for real oil and gas-condensate mixtures, including matching of the non-equilibrium condensate recovery dynamics for the late stage of production at the Vuktylskoye field.

Author:

Ilya M. Indrupskiy

Chief researcher / head of Gas-, Oil- and Condensate Recovery Lab of the Oil and Gas Research Institute of the Russian Academy of Sciences (OGRI RAS). Professor of the Applied Mathematics and Computer Modeling Department of the Gubkin State University of Oil and Gas.

Graduated from the Gubkin University with an engineering degree in applied mathematics. Doctor of technical sciences in reservoir engineering. Professor of the Russian Academy of Sciences. Author of more than 150 journal and conference papers and more than 20 patents.

Research area includes improvement of integrated 3D reservoir modeling; forward and inverse problems of fluid flow and thermodynamics in oil and gas reservoirs; development of highly informative well testing and data interpretation methods; advancements in production techniques for hard-to-recover hydrocarbons.

Ilya has a considerable experience in research projects for the Russian Academy of Sciences, as well as for Gazprom Neft, TNK-BP, Rosneft, Lukoil, Gazprom and other companies.

Reliable information about reservoir properties and its variation within the reservoir is a key factor in reducing uncertainty within the choice of an asset development strategy, technological solutions, estimation of recoverable reserves and feasibility of development strategies. In case of waterflood designing or other methods of pressure maintenance for inhomogeneous, anisotropic collector, among necessary initial parameters we need the most accurate data on displacement efficiency, relative phase permeability functions, permeability values ​​along lateral and vertical coordinates, and principal directions of permeability tensor for complex carbonate objects. All those characteristics are currently determined from data of laboratory core studies, with total impossibility to transfer it correctly to the scale and conditions of fluid flow in formation during field development.

For 15 years the authors have been developing new methods and technologies for complex well testing. For each type of research, a specially planned sequence of technological operations, extended complex of hydrodynamic, geophysical measurements and methods production logging provide highly informative data on multidimensional multiphase filtration processes directly at reservoir conditions.

To determine desired reservoir characteristics, obtained data are interpreted by data assimilation within inverse problem solution. Corresponding forward problems are solved in transient, multiphase and / or multidimensional statement, with full consideration for object peculiarities (heterogeneity and anisotropy of formation properties, compressibility of fluids and rocks, possibility of separating dissolved gas, variable mineralization of water, etc.). Solution of corresponding inverse problems is carried out using effective optimization methods and methods of optimal control theory (adjoint method). Algorithms and software have been developed for numerical solution of forward and inverse problems.

A series of patents has been obtained for new methods of well testing and related technical solutions. Technologies are tested on a number of domestic deposits. Substantial results are obtained, new interesting effects are revealed.

Our presentation will highlight the main ideas, achieved results and accumulated experience, with an emphasis on the scientific component of topic considered.

S.N. Zakirov, E.S. Zakirov, I.M. Indrupsky, 
D.P. Anikeev, T.N. Tsagan-Mandjiev, M.N. Baganova, OGRI RAS

Author:

Ernest S. Zakirov

Professional Characteristic

Doctor of Technical Sciences, Professor of the Russian Academy of Sciences E.S. Zakirov is a leading scientist in the field of modeling oil and gas fields development, development optimization of natural hydrocarbon deposits, history matching of 3D hydrodynamic models, specialized well testing, and an expert in domestic oil and gas projects.

E.S. Zakirov already has published over 225 scientific works, including 7 monographs and 1 book, possesses more than 40 patents for inventions, including international (USA). Prepared 5 candidates of sciences. He is also SPE member.

Education

In 1991 he graduated cum laude from Moscow State University named after M.V. Lomonosov.

In 1991-1994 years – post-graduate student of Moscow State University named after M.V. Lomonosov.

In 1997 he defended his candidate degree.

In 2001 he defended his doctoral dissertation.

In 2015, he was elected professor of the Russian Academy of Sciences by the Department of Earth Sciences of the Russian Academy of Sciences.

Professional activity

1994 to present time

Principal Researcher of the Gas-Oil-Condensate Recovery Laboratory of Oil and Gas Research Institute of Russian Academy of Sciences.

Creates new and improves existing technologies for oil and gas fields development.

Along with fundamental research, he is engaged in designing and improving development of oil and gas fields, including Yaro-Yakhinskoye, Western Siberia (1997), Severo-Vasyuganskoye, Tomsk Region (1998), Talinskoe field, Western Siberia (2000), Pribrezhnoye field (2001), Prirazlomnoye, the Barents Sea (2002), the Novogodnee. West Siberia (2006).

Since 1991, he has been conducting joint scientific research with Statoil, Norsk Hydro, Verbundnetz Gas, YUKOS, SIDANKO, Lukoil, Rosneft, TNK-BP and other companies.

To increase the efficiency of field development, more and more wells are drilled with horizontal or high angle section at the end (HAHZ). Despite this, well logging data analysis is based on methodic and models developed using data from vertical and slant wells with relatively low inclination angle. Although it works well for vertical wells, it does not take into account geometric effects associated with high angle of drilling where wells are drilled almost parallel to formation layers. That often leads ambiguities while logging data analysis and formation evaluation in HAHZ wells compared to low angle wells. This fact does not allow using logging data from horizontal wells for geological and hydrodynamic models, which reduces its credibility.

The presentation describes uncertainties that exist when using conventional processing and interpretation techniques in horizontal wells and their causes. For demonstration purpose, the paper uses an example from real well, which has been drilled horizontally in complex environment in one of the field of Western Siberia region of Russia.

Azimuthal measurements application together with advanced modeling software packages enable more reliable estimation of well length exposed to reservoir, spatial position of its boundaries and essential reservoir properties, such as porosity and saturation. As a result, the geological model may be refined locally.

Author:

Bokarev Anton, Schlumberger

Anton was graduated as Oil ang Gas geologist in the Tyumen Industrial University in 2008. At Schlumberger, he has taken the path from the Field Engineer to the international Logging-While-Drilling instructor. He took part in projects in Western and Eastern Siberia, the Timano-Pechora and Caspian regions. Has experience working for foreign projects in the UAE and Oman. Currently he holds the position of Senior Petrophysicist at Schlumberger in Tyumen. The field of expertise of the author is the Logging While Drilling technologies and its practical application. He is the author of 10 scientific articles and patents. Has experience working and teaching abroad.

Event will take place on December 4,Monday, at 1830 hours.

Gathering guests at 18.30 in the Congress Center of the RF CCI, entrance by invitation.

In order to receive an invitation, please write to This email address is being protected from spambots. You need JavaScript enabled to view it., the letter should indicate your full name, place of work and position.

Applications are accepted until 12.00, on 30 November.