Calculation Methods for Linear and Radial Steam Flow in Oil Reservoirs

1983 ◽  
Vol 23 (03) ◽  
pp. 427-439 ◽  
Author(s):  
J. van Lookeren
Keyword(s):  
Laboratory Experiments ◽  
Steam Injection ◽  
Injection Rate ◽  
Hot Water ◽  
Oil Reservoirs ◽  
Steam Flow ◽  
Volatile Components ◽  
Calculation Methods ◽  
Oil Viscosity ◽  
Injection Wells

Abstract The flow of oil and water in a reservoir as a result of steam injection is related to the shape of the growing steam zone. Analytical formulas describing the approximate shape of this zone have been derived both for linear flow in horizontal and dipping formations and for radial flow around injection wells in a horizontal formation. The theory is based on segregated-flow principles such as those previously used by Dupuit,1 Dietz,2 and others. The formulas take into account gravity overlay of steam zones and have been checked against results of scaled laboratory experiments, steam-injction projects in the field, and calculations with a numerical reservoir simulator. From the good agreement with the new calculation method it would seem that the shape of a steam zone is controlled mainly by one group of parameters including steam-injection rate, pressure, and effective formation permeability to steam. The equations can be used to analyze and explain field observations, such as the position of steam/liquid contacts in injection wells, estimates of effective permeability to steam in steam zones, and steam-zone thickness as noticed in observation wells. This paper shows, for example, how a cumulative oil/steam ratio for oil displaced from a steam zone depends on steam-zone pressure, injection rate, and time. With increasing oil viscosity, more bypassing of oil by steam owing to viscous forces will occur, leading to more overlay of steam zones and eventually to narrow tonguing in a lateral direction. The calculation methods provide an evaluation tool for steam drive and steam-soak processes to reservoir engineers engaged in field operations, project design, and research. Introduction The reservoir engineer is often confronted with many day-to-day problems in designing, planning, and starting up steam-injection projects and monitoring their performance analysis and improvement in which fast and simple, although approximate, engineering calculation methods could be used to advantage. By presenting calculation methods for linear and radial steam flow in oil reservoirs, a tool is provided to gain a better understanding of the shape and growth of steam zones in reservoirs subjected to steam injection. A selection has been made from reservoir engineering literature, laboratory experiments, and field data to introduce the essentials of the calculation methods for making estimates with respect to performance, sweep efficiency, optimization, etc., of steam-injection processes in actual oil reservoirs. Oil displaced from steam zones is calculated, but no attempt has been made to arrive at a full prediction tool for oil production from reservoirs by adding calculations for oil quantities displaced by cold- and hot-water drives and even miscible drives, if the oil has volatile components. With the present capacities of mathematical reservoir simulation programs, adequate integration of simultaneously occurring oil-displacement processes seems more appropriate for the large computer.

scholarly journals Experimental study on the mechanism and development effect of multi-gas assisted steam huff and puff process in the offshore heavy oil reservoirs

2021 ◽  
Author(s):  
Jie Fan ◽  
Zuqing He ◽  
Wei Pang ◽  
Daoming Fu ◽  
Hanxiu Peng ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Oil Reservoirs ◽  
Viscosity Reduction ◽  
Oil Viscosity ◽  
Enhanced Production ◽  
Heavy Oil Reservoirs ◽  
Water Gas ◽  
Development Mechanism

AbstractMulti-gas assisted steam huff and puff process is a relatively new thermal recovery technology for offshore heavy oil reservoirs. Some blocks of Bohai oilfield have implemented multi-gas assisted steam huff and puff process. However, the development mechanism still requires further study. In this paper, high-temperature high-pressure (HTHP) PVT experiments and different huff and puff experiments of sand pack were carried out to reveal the enhanced production mechanism and evaluate the development effect of multi-gas assisted steam huff and puff process. The results indicated that viscosity reduction and thermal expansion still were the main development mechanism of multi-gas assisted steam huff and puff process. Specifically, CO2 easily dissolved in the heavy oil that made it mainly play the role of reducing oil viscosity, N2 was characteristics of small solubility and good expansibility, and it could improve formation pressure, increase steam sweep volume and even reduce the heat loss. Meanwhile, injecting multi-gas and steam could break the balance of heavy oil component that made the content of resin reduce and the content of saturates, aromatics and asphaltene increase so as to further reduce the viscosity of heavy oil. Compared with steam huff and puff process, multi-gas assisted steam huff and puff process increased the recovery by 2–5%. The optimal water–gas ratio and steam injection temperature were 4:6 and 300℃, respectively. The results suggested that multi-gas assisted steam huff and puff process would have wide application prospect for offshore heavy oil reservoirs.

scholarly journals An integrated heat efficiency model for superheated steam injection in heavy oil reservoirs

2019 ◽  
Vol 74 ◽  
pp. 7 ◽  
Author(s):  
Congge He ◽  
Anzhu Xu ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Angang Zhang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Steam Injection ◽  
Injection Rate ◽  
Total Heat ◽  
Oil Reservoirs ◽  
Injection Time ◽  
New Model ◽  
Heat Efficiency ◽  
Heavy Oil Reservoirs

Accurate calculation of heat efficiency in the process of superheated steam injection is important for the efficient development of heavy oil reservoirs. In this paper, an integrated analytical model for wellbore heat efficiency, reservoir heat efficiency and total heat efficiency was proposed based on energy conservation principle. Comparisons have been made between the new model results, measured data and Computer Modelling Group (CMG) results for a specific heavy oil reservoir developed by superheated steam injection, and similarity is observed, which verifies the correctness of the new model. After the new model is validated, the effect of injection rate and reservoir thickness on wellbore heat efficiency and reservoir heat efficiency are analyzed. The results show that the wellbore heat efficiency increases with injection time. The larger the injection rate is, the higher the wellbore heat efficiency. However, the reservoir heat efficiency decreases with injection time and the injection rate has little impact on it. The reservoir thickness has no effect on wellbore heat efficiency, but the reservoir heat efficiency and total heat efficiency increase with the reservoir thickness rising.

An Improved Simulation for Interpreting Temperature Logs in Water Injection Wells

1982 ◽  
Vol 22 (05) ◽  
pp. 709-718 ◽  
Author(s):  
John Fagley ◽  
H. Scott Fogler
Keyword(s):  
Heat Transfer ◽  
Digital Computer ◽  
Water Injection ◽  
Steam Injection ◽  
Hot Water ◽  
Injection Wells ◽  
Short Period ◽  
Injection Zone ◽  
Wellbore Temperature ◽  
Laplace Transformations

Abstract An improved simulation for temperature logs (TL's) in water injection wells is described. Improvements based on the reduction of assumptions used by previous investigators are demonstrated by comparison of field data and simulator results showing excellent agreement of TL profiles over the entire well depth. Initial work with the simulator has demonstrated the need for different operational procedures for definite TL surveys in mature wells (those having received significant long-term injection) as compared with young wells. The utility of short-period hot water (SPHW) injection just preceding shut-in as an injection profile amplifying scheme has been investigated in depth through the TL simulator. Finally, sensitivity studies have been run to identify the most important TL parameters and to develop guidelines for improved profiling. Introduction Injection of water into wells is done for three basic reasons: to maintain field pressure, for waterflooding, or to dispose of unwanted brine. For at least two of these it is desirable to know an injection profile. The TL is one way of defining injection profiles and is particularly useful in wells with outside-of-casing vertical flow.As fluid flows down the wellbore, the rock surrounding the wellbore (which is initially at the prevailing geothermal temperature) is heated or cooled by the injection water, depending on its temperature and the rate of heat transfer in the well. This effect is most pronounced in an injection zone where the fluid enters the rock formation, flowing radially outward, and where heat transfer occurs by both convection arid conduction. Except for hot-water and steam injection, the near-wellbore portion of the flooded zone normally will be cooled. Once the well is shut in and fluid flow is halted, the temperature of the well and the surrounding formation starts to return to the original geothermal temperature. The regions above and below the injection zone trend toward the geothermal temperature more rapidly than in the injection zone because of the greater heat transfer in the latter. Thus, by measurement of the wellbore temperature as a function of depth the location of the injection zone can be determined as the region where temperature anomalies occur.The interpretation of TL's to determine injection flow profiles has been attempted previously, both qualitatively and quantitatively. In early studies, quantitative analysis was made by use of Laplace transformations and Bessel function solutions. With the advent of the digital computer, more rigorous analysis can be made with numerical methods to treat heat transfer terms, which had to be removed by simplifying assumptions in the earlier studies.In this paper, we present an improved injection-well temperature simulator of the digital computer variety. This simulator offers an advantage over previous simulators in that wellbore-water heat transfer is modeled both before and after shut-in of the well. This capability allowed us to investigate possible solutions to the problem of lost profile definition in mature injection wells. We have found hot-water injection, for a short period before shut-in, to be a potentially important tool for defining injection fluid profiles in mature wells. SPEJ P. 709^

Steam Zone Growth During Multiple-Layer Stream Injection

1967 ◽  
Vol 7 (01) ◽  
pp. 1-10 ◽  
Author(s):  
P.J. Closmann
Keyword(s):  
Vertical Direction ◽  
Single Layer ◽  
Steam Injection ◽  
Injection Rate ◽  
Oil Viscosity ◽  
Layer System ◽  
Small Times ◽  
Generating Capacity ◽  
Thermal Techniques ◽  
Equal Thickness

Abstract The development of multiple parallel steam zones of equal thickness and uniform separation is described mathematically. At small times, the growth of one of the steam zones is independent of the presence of the orders. At long times, simple relationships are obtained which describe the growth of the steam zones. Generally, it is found desirable to allow steam to penetrate the underground reservoir at a number of vertical positions if sufficient steam-generating capacity is available to maintain comparable injection rates in all the layers. If a limited steam-generating capacity is available, the larger steam zone volume is created in the single-layer system. Introduction The use of hot fluid injection as a means of lowering oil viscosity in petroleum reservoirs is becoming increasingly common. Prominent among the thermal techniques being used is steam injection. The basic mechanisms involved when steam flows through oil-containing porous rock have been reported by Willman et al. The growth of the steam zone when steam enters a single layer at constant injection rate has been developed by Marx and Langenheim. Frequently, an underground formation is stratified and presents a number of horizontal paths for the injected fluid to follow. This paper considers the steam zone development when a large number of highly permeable paths of equal thickness, separated by arbitrary but equal distances, are available for flow of injected steam. THEORY Consider the system shown in Fig. 1. A number of horizontal zones of equal thickness, hs are separated from each other at distances 1. It is assumed that there are infinitely many layers in the vertical direction. Further, important assumptions of the mathematical model to be employed are as follows.Steam enters all the layers at constant and equal rates.Steam zone temperature remains constant throughout the steam zone at the value of the input steam temperature.The heat capacity of the steam zone may be represented by some average value.Heat loss occurs normal to the horizontal boundaries of the steam zones.No heat is transported by conduction or convection ahead of the steam front. The formation immediately ahead of the steam zone remains at original reservoir temperature. The shape of the temperature distribution will then be that of a step which moves outward.At each position in space the fluid and rock temperatures are equal. STEAM ZONE LAYER OF FINITE AND NONZERO THICKNESS SPEJ P. 1ˆ

A Two-Dimensional Analysis of Reservoir Heating by Steam Injection

1971 ◽  
Vol 11 (02) ◽  
pp. 185-197 ◽  
Author(s):  
Satter Abdus ◽  
David R. Parrish
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Water Injection ◽  
Injection Pressure ◽  
Steam Injection ◽  
Injection Rate ◽  
Hot Water ◽  
Liquid Zone ◽  
Radial Heat ◽  
The Difference

Abstract The widely used Marx and Langenheim solution for reservoir heating by steam injection fails to account for the growth of the hot liquid zone ahead of the steam zone. Furthermore, that solution does not consider radial heat conduction both within and outside the reservoir and vertical conduction within the reservoir. In the present paper, a more realistic and generalized solution is provided by eliminating several restrictive assumptions of the ‘old theory'. However, fluid flow is not considered in this model. The partial-difference equations that describe the condensation within the steam zone and temperature distribution within the system have been solved by finite-difference schemes. Calculated results are presented to show the effects of steam injection pressures ranging from 500 to 2,500 psia and rates, 120 and 240 lb/hr-ft, on the growth of the steam and hot liquid zones. A 50-ft thick reservoir with fixed thermal and physical characteristics was considered. Results show that heat losses from the reservoir into the surrounding rocks are not greatly different from those predicted by Marx and Langenheim. However, the heat distribution is markedly different. A sizable portion of the reservoir heat was contained in the hot liquid zone which grows indefinitely. This means that heat (warm water) could arrive at the producing wells sooner than predicted by the old theory. This is particularly true for low injection rate or high injection pressure. Curiously, for a given injection rate and pressure, the heat content of the hot liquid zone remains (except for early times) essentially a constant percentage of the cumulative heat injected. INTRODUCTION In 1959. Marx and Langenheim1 made a theoretical study of reservoir heating by hot fluid injection. Their solution has been widely used in the industry for the evaluation of the steam-drive process. This solution, however, is based upon an unrealistic assumption that the growth of the hot liquid zone ahead of the steam zone is negligible. Therefore, it cannot predict the arrival of warm water at the producing wells earlier than steam. Furthermore, in the so-called ‘old theory', radial heat conduction both within and outside the reservoir was neglected. Willman et al.2 presented another analytical solution of the same problem. Their solution is comparable to the Marx-Langenheim solution and suffers from the same disadvantages. Wilson and Root3 presented a numerical solution for reservoir heating by steam injection. While radial and vertical heat conduction both within and outside the reservoir were considered, their solution was provided essentially for the injection of a noncondensable fictitious hot fluid. The specific heat of the injected fluid was assumed to be equal to the difference between the enthalpy of steam and the enthalpy of water at the reservoir temperature divided by the difference in the two temperatures. Baker4 carried out an experimental study of heat flow in steam flooding using a sand pack. 4 in. thick and 6 ft in diameter. The steam injection pressure was 2 to 5 psig and rates ranged from 22 to 299 lb/hr-ft. He showed that a significant portion of the injected heat was contained in the hot water zone. The theoretical steamed or heated volume, as calculated by the Marx and Langenheim method, fell between the experimental steamed and heated (including hot water) volumes. Spillette5 made a critical review of the known analytical solutions dealing with heat transfer during hot water injection into a reservoir. These solutions are based upon many restrictive assumptions similar to the simplified solutions of the steam heating process. Spillette also presented a numerical solution for multidimensional heat transfer problems associated with hot water injection and demonstrated the utility and accuracy of the method. Most mathematical models of steam and hot water recovery processes neglect fluid flow considerations.

scholarly journals Screening of waterflooding, hot waterflooding and steam injection for extra heavy crude oil production from Tatarstan oilfield

2021 ◽  
Vol 931 (1) ◽  
pp. 012002
Author(s):  
A Pituganova ◽  
I Minkhanov ◽  
A Bolotov ◽  
M Varfolomeev
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Water Injection ◽  
Oil Production ◽  
Steam Injection ◽  
Hot Water ◽  
Heavy Crude Oil ◽  
Oil Viscosity ◽  
Heavy Crude ◽  
Bulk Model

Abstract Thermal enhanced oil recovery techniques, especially steam injection, are the most successful techniques for extra heavy crude oil reservoirs. Steam injection and its variations are based on the decrease in oil viscosity with increasing temperature. The main objective of this study is the development of advanced methods for the production of extra heavy crude oil in the oilfield of the Republic of Tatarstan. The filtration experiment was carried out on a bulk model of non-extracted core under reservoir conditions. The experiment involves the injection of slugs of fresh water, hot water and steam. At the stage of water injection, no oil production was observed while during steam injection recovery factor (RF) achieved 13.4 % indicating that fraction of immobile oil and non-vaporizing residual components is high and needed to be recovered by steam assisted EORs.

A Study on Effect Evaluating and Parameters Sensitivity Analyzing of Superheated Steam Soak in Heavy Oil Reservoirs

2011 ◽  
Vol 239-242 ◽  
pp. 3069-3073 ◽  
Author(s):  
Qiang Zheng ◽  
Hui Qing Liu ◽  
Zhan Xi Pang ◽  
Fang Li
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Oil Production ◽  
Steam Injection ◽  
Injection Rate ◽  
Oil Reservoirs ◽  
Saturated Steam ◽  
Production Volume ◽  
Heavy Oil Reservoirs ◽  
Recovery Percentage

By using the technology of numerical reservoir simulation, we have compared superheated steam soak with saturated steam soak in area of heating, effect of distillation, capability of increasing oil production, volume of steam in need to evaluate the effect of superheated steam soak in heavy oil reservoirs. Analyzed the sensitivity of parameters like steam injection intensity, steam injection rate, soak time, degree of superheat to conclude the rule that they affect on recovery percentage. The research shows that, heating radius of superheated steam is greater than that of saturated steam, distillation effect of superheated steam is better than that of saturated steam, oil production of superheated steam is more than that of saturated steam, steam volume in need of superheated steam is less than that of saturated steam. Recovery percentage of superheated steam soak increases but more and more slowly with the increase in steam injection intensity, increases first and then decreases with the increase in steam injection rate, increases first and then decreases with the increase in soak time, increases but more and more slowly with the increase in degree of superheat. Influence of steam injection intensity is obvious to recovery percentage, but influence of other factors like soak time, steam injection rate, degree of superheat is insignificant.

THE VARIATION OF TEMPERATURE OF DIFFERENT OIL RESERVOIR DENSITIES EXPLOITED BY THERMAL METHODS

2020 ◽  
Author(s):  
Ionescu (Goidescu) Nicoleta Mihaela ◽  
Vasiliu Viorel Eugen ◽  
Onutu Ion
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Steam Injection ◽  
Oil Reservoirs ◽  
Oil Viscosity ◽  
Thermal Methods ◽  
Injection Process ◽  
Heavy Oil Reservoirs ◽  
The World ◽  
Recovery Methods

Enhanced oil recovery (E.O.R) is oil recovery by the injection of materials not normally present in the reservoir. Thermal methods such as steam injection process are the best heavy oil recovery methods. Improvement of mobility ratio in the reservoir and economic recovery from heavy oil reservoirs depend mainly on reduction of heavy oil viscosity. For a steam injection process should consider the heat and mass transfer. Heavy oil reservoirs contain a considerable amount of hydrocarbon resources of the world. Meanwhile further demand for oil resources in the world , reduction of natural production from oil reservoirs, and finally price of oil in recent years have attracted notices to production methods from heavy and extra heavy oil reservoirs. High viscosity and great amounts of asphaltene in these hydrocarbons make difficulties in extraction, transportation, and process of heavy oil. In Romania there have been numerous theoretical and laboratory researches, as well as site experiments on the application of secondary recovery methods,Romanian specialists having a wide experience in this field

Sign in / Sign up

Export Citation Format

Share Document