Showing papers on "Steam injection published in 1993"

Monitoring an underground steam injection process using electrical resistance tomography

Abstract: We used electrical resistance tomography (ERT) to map the subsurface distribution of a steam flood as a function of time as part of a prototype environmental restoration process performed by the Dynamic Underground Stripping Project. We evaluated the capability of ERT to monitor changes in the soil resistivity during the steam injection process using a dipole-dipole measurement technique to measure the bulk electrical resistivity distribution in the soil mass. The injected steam caused changes in the soil's resistivity because the steam displaced some of the native pore water, increased the pore water and soil temperatures and changed the ionic content of the pore water. We could detect the effects of steam invasion by mapping changes in the soil resistivity as a function of space and time. The ERT tomographs are compared with induction well logs, formation temperature logs and lithologic logs. These comparisons suggest that the ERT tomographs mapped the formation regions invaded by the steam flood. The data also suggest that steam invasion was limited in vertical extent to a gravel horizon at depth of approximately 43 m. The tomographs show that with time, the steam invasion zone extended laterally to all areas monitored by the ERT technique.

Gas turbine dual fuel nozzle assembly with steam injection capability

Abstract: A fuel nozzle assembly is provided having the capability of burning either gaseous or liquid fuel, or both simultaneously, along with steam injection. The nozzle has a nozzle body that is attached to a nozzle cap by inner, outer and middle sleeves. The sleeves form inner and outer concentric annular conduits between themselves for directing the flow of gaseous fuel and steam from the fuel and steam inlet ports to the outlet ports. In addition, the inner sleeve forms a central chamber in which an oil fuel nozzle is disposed. Radial passages in the nozzle body allow cooling air to flow over the oil nozzle and through the oil outlet port, thereby preventing coking at the nozzle tip. The fuel nozzle assembly is originally built, and the nozzle cap is replaced, by sliding the sleeves forward and aft on the assembly so as to gain access to the next innermost sleeve.

Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

Abstract: A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process.

Effects of hydrocarbon spills from an oil pipeline break on ground water. Technical report

Abstract: The study was undertaken to determine the effect of an oil spill, which might be caused by a seismic event rupturing a crude oil pipe line which crosses the recharge area of the Memphis Sands Aquifer. To do this, two numerical models were used to simulate a potential rupture of the 40 inch crude oil pipeline located in Wolf River fluvial valley susceptible to liquefaction. The simulation approach used two two-dimensional upstream weighted finite element models to predict the three-dimensional flow phenomenon of released crude in the saturated and unsaturated zones. ARMOS (Areal Multiphase Organic Simulator) was used to simulate the crude oil migration horizontally and to evaluate the extent of the crude dispersion on the ground water table.

Steamflood reservoir management : thermal enhanced oil recovery

Abstract: This work describes in detail state-of-the-art concepts, tools and procedures used in steam injection procession - cyclic and continuous steam injection).

Comparative Evaluation of Combined Cycles and Gas Turbine Systems With Water Injection, Steam Injection and Recuperation

Abstract: Combined cycles have gained widespread acceptance as the most efficient utilization of the gas turbine for power generation, particularly for large plants. A variety of alternatives to the combined cycle that recover exhaust gas heat for re-use within the gas turbine engine have been proposed and some have been commercially successful in small to medium plants. Most notable has been the steam injected, high-pressure aero-derivatives in sizes up to about 50 MW. Many permutations and combinations of water injection, steam injection, and recuperation, with or without intercooling, have been shown to offer the potential for efficiency improvements in certain ranges of gas turbine cycle design parameters.A detailed, general model that represents the gas turbine with turbine cooling has been developed. The model is intended for use in cycle analysis applications. Suitable choice of a few technology description parameters enables the model to accurately represent the performance of actual gas turbine engines of different technology classes. The model is applied to compute the performance of combined cycles as well as that of three alternatives. These include the simple cycle, the steam injected cycle and the dual-recuperated intercooled aftercooled steam injected cycle (DRIASI cycle). The comparisons are based on state-of-the-art gas turbine technology and cycle parameters in four classes: large industrial (123–158 MW), medium industrial (38–60 MW), aeroderivatives (21–41 MW) and small industrial (4–6 MW). The combined cycle’s main design parameters for each size range are in the present work selected for computational purposes to conform with practical constraints.For the small systems, the proposed development of the gas turbine cycle, the DRIASI cycle, are found to provide efficiencies comparable or superior to combined cycles, and superior to steam injected cycles. For the medium systems, combined cycles provide the highest efficiencies but can be challenged by the DRIASI cycle. For the largest systems, the combined cycle was found to be superior to all of the alternative gas turbine based cycles considered in this study.Copyright © 1993 by ASME

The effects of steam injection on the electrical conductivity of an unconsolidated sand saturated with a salt solution

Abstract: The spatial and temporal variation of electrical conductivity in saturated sands during steam injection has been measured and modeled. Experiments consisted of introducing steam into one end of a tube filled with sand saturated with a slightly saline solution. A steam condensation front formed, separating the mixed-phase steam zone from the liquid zone. Measurements of electrical conductivity were made at 10 locations along the tube using a four-electrode technique. Results show that conductivity starts at a constant value, decreases before the steam front arrives and then, immediately prior to the steam front arrival, goes through a maximum before dropping by a factor of about 25. These variations can be explained by first, a dilution of the interstitial solution causing the initial drop in conductivity; second, an increase in temperature of the solution immediately prior to the arrival of the steam front causing the conductivity maximum; and finally, the large drop in conductivity due to the combined effects of a decrease in saturation and dilution of the residual liquid in the two-phase zone. Mathematical solutions of a set of differential equations that take into consideration all of these effects are presented. These solutions reproduce the significant features of the conductivity data.more » This study suggests that the measurement of changes in the subsurface conductivity field during steam injection operations may indicate the location of ionic concentration, temperature, and steam saturation fields. 28 refs., 7 figs., 1 tab.« less

An Update Of Steam Injection Operations At Naval Petroleum Reserve No. 3, Teapot Dome Field, Wyoming: A Shallow Heterogeneous Light Oil Reservoir

Abstract: The Shannon light-oil (32-34° API gravity) steamflood at Naval Petroleum Reserve No. 3, (NPR-3) Teapot Dome field, Wyoming, was initiated in 1985 as a result of favorable production response to steam preheating in the in situ combustion pilot carried out in the early 1980's. Favorable but mixed success of two 10-acre steamflood pilots led to commercial scale operation in 1987. To date, the steamflood project has steamed 210 acres, 90 acres of which is currently being steamed with three 50 MMBtu/hr steam generators. The performance of the steamflood is reviewed in light of the dominant role that the reservoir's complex geology plays, since both injection and production wells are greatly influenced by the localized, highly heterogeneous geology of the consolidated, tight, faulted, and extensively fractured sandstone composing the Upper and Lower Shannon. Pattern step out is dominated by the geologic conditions that dictate each pattern's operation. Economics, mandates for profitability, and budget constraints have influenced the method by which the steamflood has been managed. Investigations of lower injection rate, variation in steam quality and the associated production response, as well as improvements in heat management techniques, are discussed. Increasing steam quality in pattern 5A led to incremental oil production of 44 B/D and a 2.5 times return on investment on the incremental gas used to fire the steam generator. Optimization of the steamflood depends upon accumulating and using information from pattern-specific operations.

Laboratory Studies of Steam Stripping of LNAPL-Contaminated Soils

Abstract: Bench‐scale laboratory experiments were conducted to evaluate the effectiveness of steam injection for in situ remediation of soils contaminated by light nonaqueous‐phase liquids (LNAPLs). Several parametric studies were performed with various combinations of soils, LNAPLs, and steam injection conditions. An increase in steam injection pressure produced a significant increase in LNAPL recovery efficiency. An increase in steam injection pressure from 12.4 to 44.8 kPa resulted in increased LNAPL recovery efficiency from 86 to 95% after one pore volume of steam injection. Higher steam injection pressure yielded maximum LNAPL recovery efficiency in significantly less time and required a smaller amount of steam than at low pressure. An increase in soil grain size or an increase in grain‐size‐distribution slope resulted in increased LNAPL recovery efficiency. The final LNAPL residual saturation was approximately 0.5% for coarse‐grained soils and 1.8% for soils with finer grain sizes. Soils with finer g...

A Model Describing Steam Circulation in Horizontal Wellbores

Abstract: A model to evaluate heat losses, steam quality, and pressure profiles during steam circulation in a horizontal wellbore was developed. The model simulates countercurrent flow stream and accounts for the interaction of heat transfer, fluid flow, phase changes, slippage between steam and water, and flow regime changes. Development of this model arose from a need to determine the wellbore heat-loss distribution during the warm-up phase in Mobil Oil Canada (Mocan's) horizontal well at Cold Lake. Results from the model were verified with actual field data.

Method and apparatus for improved oil recovery of oil and bitumen using dual completion cyclic steam stimulation

Abstract: A method and apparatus whereby recovery from heavy oil and bitumen reservoirs may be increased over that achieved in the later stages of cyclic steam stimulation (CSS) operations. Two sets of perforations perforate a steam chamber in a reservoir surrounding a well. The two sets of perforations are isolated hydraulically from each other within the casing by a thermal packer. Steam is then injected down the casing annulus into the upper set of perforations. After a period of steam injection, steam injection is halted and hydrocarbons are produced from the lower set of perforations through one of two strings of tubing extending through the thermal packer. The second string of tubing serves to vent the well during production. This process may be repeated over the life of the well, alternately injecting steam and producing hydrocarbons.

Enhance performance of soil vapor extraction

Abstract: Hydrocarbon recovery as a means of soil and groundwater remediation has received considerable attention in the last few years as the shortcomings of groundwater pump-and-treat technologies have become more evident. A previous article covered a wide range of in situ site cleanup technologies and provided guidance on how to choose among them. This article examines one of those technologies, soil vapor extraction (SVE), in more detail and explains how to improve the performance of SVE by combining it with air sparging or steam injection. Air sparging injects air below the groundwater surface to promote the volatilization of volatile organic compounds (VOCs) from the groundwater into the vadose zone so that the VOCs can be removed via the SVE system. Steam injection injects steam into the vadose zone to increase the subsurface temperatures, thereby volatilizing organic compounds with high boiling points.

Improvement for petroleum hydrocarbon steam cracking method

Abstract: The present invention relates to improvement on feeding mode in convection section during the ethylene prodn by steam-cracking of petroleum hydrocarbon, and it adopts twice injection mode, i.e. primary steam injection at three points and secondary steam injection at one point. There are three injection ports, upper, middle and lower, in the convection section for primary steam injection, and the admission amount for each injection port varies with different petroleum kinds. The proportion of primary steam to secondary steam is 15-60 to 85-40. The improved cracking technology is suitable for the cracking of naphtha, light diesel oil and heavy oil with a dry point below 500 deg.c.

Steam injection into a slow water flow through porous media

Abstract: Steam injection into a slow water flow (Darcy flow) was studied analytically for steady-state conditions. The continuity, momentum, and energy equations for both water flow and steam flow were solved subject to interface conditions. The governing equations were transformed using stream function and velocity potential coordinates to simplify the calculation domain. The resulting energy equation was converted to a simultaneous ordinary differential equation by an integral method. The unknown steam-water interface shape and location were determined through an optimization process. Temperature distribution on the water side, local condensation rate along the interface, water and steam flow fields and pressure distribution were found numerically

Enhancement of In-Situ Combustion by Steam Stimulation of Production Wells

Abstract: Steam stimulation of individual wells was used to improve the performance of an in-situ combustion project operated by BP Resources Canada Ltd. in the Cold Lake oil-sand deposits of northeastern Alberta. In addition, steam was used to protect production wells that were threatened by the combustion front or had experienced oxygen breakthrough. The effectiveness of these steam uses varied. This paper describes the strategy developed for the use of steam injection and case histories and draws conclusions on how to use steam injection for maximum effect.

Imaging of Reflection Seismic Wavefields In Thermally Enhanced Oil Recovery Projects

Abstract: S U M M A R Y Reservoir monitoring during an enhanced oil recovery (EOR) process is critical for efficient management of the EOR process. 3-D high resolution surface seismic is used since timelapse seismic images can monitor reservoir changes that are induced during the process. We have developed modeling and imaging algorithms, which are implemented on vector and parallel computers, for improved imaging of steam zones in two different experiments that involve in situ thermal EOR processes in the heavy oil sands at Cold Lake, Alberta, Canada. Computer simulations of seismic wave propagation were essential for the interpretation of the field data. Finite difference modeling of seismic waves in acoustic, elastic, viscoacoustic and porous media in the region over the steam-heated zone was performed in order to examine the relation between rock properties such as porosity, permeability and saturation with seismic characteristics such as velocity, amplitude and frequency modification with time. The models used in these simulations were modified until a reasonable match was obtained between the field and synthetic data. Processing of the 3-D surface reflection seismic data before and after steam injection was performed with our own algorithms and preliminary results are going to be presented. One-pass 3-D post stack depth migration in the space-frequency domain was implemented on a MIMD parallel computer. The migration includes lateral velocity variations and uses some of the detail models that we used in the modeling. During steam stimulation seismic effects such time delays of the reflectors below and amplitude changes within the steam area are important for the imaging of the heated zones on the monitor seismic data volumes. Both of these effects were observed and mapped by analysing the before (base) and after steam (monitor) 3-D seismic data.

Method and apparatus for measuring steam density by neutron method

Abstract: A method and an apparatus capable of measuring the density of steam within a steam pipe even in limited environmental conditions such as in a steam injection well. A vessel which accommodates therein first and second neutron detectors disposed in mutual longitudinal alignment with a neutron source interposed therebetween and in which the second detector is covered with a neutron shield capable of absorbing thermal neutrons while allowing epithermal neutrons to penetrate therethrough is inserted into the steam pipe together with a thermal neutron shielding sheet completely encircling the vessel. From the neutrons which were emitted from the neutron source and passed out and back through the neutron shield and the steam region, those epithermal neutrons which have not undergone transformation to thermal neutrons within the steam region are detected by both the first and second detectors, while the thermal neutrons resulting from the transformation are detected by the first detector only. The steam density is determined on the basis of a cadmium ratio derived from the counts of the two detectors.

Lpg/steam mixing combustor

Abstract: PURPOSE: To reduce the size of a device by a method wherein a casing having an LPG spraying device, a steam injection port, a mixing device thereof, and a vaporizing device for drain is provided, an LPG steam mixer having a heating means and a gas turbine combustor are provided, and steam is guided from the vaporizing device to the heating means and from the heating means to the injection port. CONSTITUTION: An LPG/steam mixing combustor comprises a gas turbine combustor 10 and an LPG/steam mixer 20. The LPG/steam mixer 20 comprises a hollow cylindrical casing 14 having a steam heating means 13; an LPG spraying device 15; a steam injection port 16; a mixing device 17 for LPG and steam; a vaporizing device 18; a heating steam line 19; an injection steam line 21: and a mixture gas line 22. This constitution uses steam used for vaporization of LPG and LPG gas for reducing NO x in common and sets working steam to one kind of high pressure steam. Further, the LPG vaporizer is of a system direct heat-exchanging with steam, and reduces the size of the device. COPYRIGHT: (C)1995,JPO

Injection Schedules and Production Strategies for Optimizing Steamflood Performance

Abstract: Methods to optimize steamflood performance of a California heavy-oil reservoir were evaluated numerically. Simulation and field results show that a reduction in steam (heat) injection rate after steam breakthrough is beneficial. A linear heat-reduction schedule resulted in the highest discounted net or salable oil production with less steam injection compared with the constant injection schedule. For unconfined patterns, steam migrates and drains oil from outside the pattern boundaries; therefore, rate reduction may not be beneficial in such cases. For mature steamfloods, conversion to hot waterflood or injector shut-in results in somewhat higher net oil production than for continued steam injection. Recompleting the producer after steam breakthrough resulted in increased recovery.

Oil sand hydrotransport tests at Syncrude Canada Ltd.

Abstract: In the Athabasca region of Northern Alberta there are major deposits of oil sands. Two large scale commercial plants are involved in mining oil sands and production of synthetic crude oil. Suncor (previously Great Canadian Oil Sands or GCOS) has been in operation since 1968 and currently produces over 25 M barrels of oil per year. Syncrude Canada Ltd. plant started operation in 1978 and currently produces over 65 M barrels (10.4 {times} 10{sup 3} m{sup 3}) of light sweet synthetic crude oil per year. Together the two operations provide 16 % of Canada`s oil output The plant located 50 km north of Fort McMurray, Alberta, is a joint venture of 9 participants. The oil sand typically contains 9 to 12 % bitumen, up to 30 % clay and 5 % water. The remainder is silica sand, finer than 150 {mu}m. Properties of oil sand are described in detail by Nonth, Ruhl and Tissot. The bulk of the plant feed is in the form of lumps ranging in size from several mm to 10 cm. It also includes lenses of soft clays and large rocks. The material is difficult to handle; sticky in summer and hard in winter. It requiresmore » special materials and design considerations for belt conveyors, transfer points, feeders etc..« less

Method for cleaning rolls and cleaning apparatus for rolls

Abstract: [57] Abstract A method and apparatus is described herein for cleaning the surface of a backing roll in a coater or a calender roll.The roll (1) is cleaned by injecting steam from a steam injection chamber (14) against the roll surface at a 15°angle counter to the rotational direction of the roll. Steam impinging on the surface performs effective removal of accumulated dirt and the detached dirt is carried away on the web without a deleterious effect on the quality of the web. Steam injected against the roll (1) is vacuumed away from the roll surface via a suction chamber (18), whereby the cleaning steam is prevented from escaping to the surroundings. (Fig. 1)

Operating method for clothes unwrinkling steam device of laundry

Abstract: PURPOSE:To provide the operating method of a clothes unwrinkling steam device of laundry smoothly filling steam in a steam box and unwrinkling the laundry efficiently and effectively CONSTITUTION:Laundry 8 is suspended in a steam box 6 provided with a ventilation path 1, an outside air guide cold-air damper 2, an outside air guide dry damper 3, a hot-air damper 4, a discharge port 5, a blast device 7, a steam injection device 9, a heating device 10, steam is filled in the steam box 6 by the discharge port 5, blast device, and steam injection device 9, and steam injecting, steaming, drying, and steam discharging operations are performed in sequence by a control system 11

Mat environments and flakeboard properties as affected by steam injection pressing variables

Abstract: Flakeboard mat vapor pressure and temperature were recorded while varying steam injection pressing treatments to determine the effect of mat environment on adhesive bonding and dimensional stability. High temperatures from severe steam treatments or extended press times were required to produce good internal bond strengths with liquid phenol-formaldehyde resol adhesives. Excellent internal bond strengths were produced with isocyanate adhesive in all steam treatments, even when press times were reduced. Increasing the severity of the steam treatment decreased water-soak thickness swelling and initial springback out of press, although initial springback was also reduced by increasing press time.