This paper will describe a methodology which has been developed as an alternative to four-dimensional (4D) Seismic. The main objective is to track heat conformance over time in the thermally developed "A" Field, Sultanate of Oman. The method has several significant advantages over 4D Seismic, including: Negligible cost and manpower requirements; Provision of close to real-time information and no processing time requirements; No Health, Safety or Environmental exposure, or disruption to ongoing operations.
Negligible cost and manpower requirements;
Provision of close to real-time information and no processing time requirements;
No Health, Safety or Environmental exposure, or disruption to ongoing operations.
The paper will also demonstrate the power of integrating wide-ranging data sources for effective well and reservoir management.
The increasingly close well spacing at "A" Field has made Seismic Acquisition progressively more challenging. Conversely, it has created an opportunity to utilize dynamic Tubing-Head Temperatures (THTs) for tracking areal thermal conformance over time. For each month in turn an automated workflow:- Grids the monthly THT averages; Integrates the production and injection data, represented as bubble plot overlays; Adds the top reservoir structure from the subsurface model, highlighting structural dip, and fault locations.
Grids the monthly THT averages;
Integrates the production and injection data, represented as bubble plot overlays;
Adds the top reservoir structure from the subsurface model, highlighting structural dip, and fault locations.
Morphing (movie) software then interpolates the monthly images to create a smoothly transitioning "Heat Movie".
The Heat Movie demonstrates the general effectiveness of the Development in terms of warming the reservoir over time. This in turn is reducing the oil viscosity and increasing production. However, it also highlights temperature anomalies that can be linked to geological features such as faults and high permeability layers. Identification of these anomalies may underpin decisions to optimise the thermal development.
In addition to the Movie, time-lapse images can be created for any chosen period. This is similar to 4D Seismic, but more powerful, since the period can be directly linked to significant field milestones, for example equal time periods before and after upgrading the steam generation process.
Proof of Concept was demonstrated in early 2018, and the technique has already been deemed sufficiently mature to utilize it for tracking and managing Thermal Conformance in place of 4D Seismic. This is resulting in annual cost savings of millions of dollars and man-years of staff time.
One potential advantage of 4D Seismic is highlighting vertical conformance. Although this is not possible using THTs alone, at "A" Field the plan is to mitigate this by integrating data from ongoing Distributed Temperature Sensing (DTS) and well temperature surveys.
Regarding applicability, the workflow can be adapted for other objectives, for example creating a movie of surface uplift and/or subsidence integrated with bubble plots of production and injection data, or water breakthrough for wells with downhole gauges, in water flood developments.
In addition to describing the methodology underpinning this innovative approach, this paper will also discuss the vision for further improving the workflow and expanding the functionality.
Hadavand, Mostafa (University of Alberta) | Carmichael, Paul (ConocoPhillips Canada) | Dalir, Ali (ConocoPhillips Canada) | Rodriguez, Maximo (ConocoPhillips Canada) | Silva, Diogo F. S. (University of Alberta) | Deutsch, Clayton Vernon (University of Alberta)
Mostafa Hadavand, University of Alberta; Paul Carmichael, Ali Dalir, and Maximo Rodriguez, ConocoPhillips Canada; and Diogo F. S. Silva and Clayton V. Deutsch, University of Alberta Summary 4D seismic is one of the main sources of dynamic data for heavy-oil-reservoir monitoring and management. Thus, the large-scale nature of fluid flow within the reservoir can be evaluated through information provided by 4D-seismic data. Such information may be described as anomalies in fluid flow that can be inferred from the unusual patterns in variations of a seismic attribute. During steam-assisted gravity drainage (SAGD), the steam-chamber propagation is fairly clear from 4D-seismic data mainly because of changes in reservoir conditions caused by steam injection and bitumen production. Anomalies in the propagation of the steam chamber reflect the quality of fluid flow within the reservoir. A practical methodology is implemented for integration of 4D seismic into SAGD reservoir characterization for the Surmont project. Introduction One of the main objectives in petroleum-reservoir modeling is to predict the future performance of the reservoir under a recovery process. It is not possible to establish the true spatial distribution of reservoir properties using limited data. Thus, the modeling process is ill-posed and subject to uncertainty (Pyrcz and Deutsch 2014). Geostatistical simulation provides a framework to quantify geological uncertainty that is represented by multiple equally probable realizations of the reservoir model. The uncertainty can be reduced by integration of all available sources of data, including static and dynamic (time-variant) data. However, each source of data provides information at different scales and levels of precision. Although there are well-established geostatistical techniques to generate stochastic realizations of the reservoir conditioned to static data, such as local measurements from wells and 2D/3D-seismic data, effective integration of dynamic data remains a major challenge. Time-lapse seismic, or 4D seismic, is one of the main dynamic sources of data for heavy-oil-reservoir monitoring and management. It contains valuable information regarding fluid movement, temperature, pressure buildup, and quality of fluid flow within the reservoir during a recovery process (Lumley and Behrens 1998; Gosselin et al. 2001). For SAGD, the evolution of the steam chamber over time is fairly clear in 4D-seismic images.
Summary Machine learning applications have drawn much attention across different industries and more recently for seismic reservoir characterization applications. In this paper, a workflow for estimation of dynamic time-lapse reservoir properties such as temperature changes ( T), water saturation changes ( Sw), gas saturation changes( Sg) and pressure changes ( Pp) in a reservoir from seismic using supervised machine learning methods have been proposed to characterize steam assisted gravity drainage (SAGD) recovery processes. Results were validated with time-lapse thermocouples from the observation wells and demonstrate the feasibility of using machine learning methods for 4D reservoir property change predictions. Introduction Use of 4D-seismic technology for reservoir monitoring has found widespread application within last few decades for various reservoir processes, including those involving steam injection (Eastwood et al, 1994). In some cases, analysis of the 4D seismic results has enabled our understanding of steam chamber growth and conformance along the well bore and in some areas resulted in improved reservoir management decisions that have had a positive effect on production.
Holyoak, S. (Petroleum Development Oman L.L.C.) | Alwazeer, A. (Petroleum Development Oman L.L.C.) | Choudhury, S. (Petroleum Development Oman L.L.C.) | Sawafi, M. (Petroleum Development Oman L.L.C.) | Belghache, A. (Petroleum Development Oman L.L.C.) | Aulaqi, T. (Petroleum Development Oman L.L.C.) | Bahri, S. (Petroleum Development Oman L.L.C.) | Yazidi, R. (Petroleum Development Oman L.L.C.) | Yahyai, A. (Petroleum Development Oman L.L.C.) | D'Amours, K. (Petroleum Development Oman L.L.C.)
Petroleum Development Oman's "A" Field Thermal Asset, southern Sultanate of Oman, is characterized by a large scale Steam Drive/Cyclic Steam Soak (CSS) development project, underpinned by extensive data gathering. Cambrian faulted/fractured braided river sandstones are the predominant reservoir, with < 300m of heavy oil. Viscosity is high, reaching up to 400,000 cP At around 1100m tvd, the reservoir is relatively deep for a thermal project. Well count is high, and steadily increasing.
Viscosity is high, reaching up to 400,000 cP
At around 1100m tvd, the reservoir is relatively deep for a thermal project.
Well count is high, and steadily increasing.
These factors create a challenging environment for maximising oil recovery. Key to success is efficient execution of data management and analysis, within a visualization intensive, collaborative work environment. In this paper we aim to demonstrate that working in this manner, within a cross-discipline asset environment enables the rapid identification and execution of cost-effective optimization opportunities and risk reduction.
In order to provide a sufficiently broad description of how the Asset is working towards the desired outcome, the paper addresses the following elements:- Data Capture, Transmission and Storage. Application of original algorithms and tools to convert the data into meaningful insights. Accessibility to insights (speed and mode of access). Meaningful impact to efficiency, production, and safety. Added value associated with the implementation.
Data Capture, Transmission and Storage.
Application of original algorithms and tools to convert the data into meaningful insights.
Accessibility to insights (speed and mode of access).
Meaningful impact to efficiency, production, and safety.
Added value associated with the implementation.
Some of the areas further discussed include the following:- Implementation of Automatic Beam-Pump Optimisation has resulted in step-changes in terms of both oil production and reduced manpower requirements. Distributed Temperature Sensing (DTS) wells are providing real-time temperature profiles, essential for monitoring steam conformance. Automated well tests are fully operational in "A" East Field, and the results can be viewed and analysed via desktop applications in the Asset. 6 Micro-Seismic wells have been successfully executed and now provide real time monitoring of reservoir integrity. A live subsurface model has been developed, which can be rapidly updated with new drilling results and subsurface insights.
Implementation of Automatic Beam-Pump Optimisation has resulted in step-changes in terms of both oil production and reduced manpower requirements.
Distributed Temperature Sensing (DTS) wells are providing real-time temperature profiles, essential for monitoring steam conformance.
Automated well tests are fully operational in "A" East Field, and the results can be viewed and analysed via desktop applications in the Asset.
6 Micro-Seismic wells have been successfully executed and now provide real time monitoring of reservoir integrity.
A live subsurface model has been developed, which can be rapidly updated with new drilling results and subsurface insights.
The above elements are continuously facilitating asset management, whilst also highlighting opportunities and reducing uncertainty as we follow the data journey from scoping and capture through to bottom line impact.
E&P has become a margin business, with relentless pressure on cost performance and global competition for capital. As operators consider how to achieve further reductions in unit operating costs, the leadership team should focus on long-term value. During a panel discussion on what fractures look like, one expert added a significant qualifier to the title: what they “may look like.” After 3 harsh years of budget cuts and layoffs, oilfield services companies are beginning to see a recovery take shape. Statoil’s integrated operations center on the Norwegian continental shelf is one of several initiatives operators and service companies have set in motion to improve condition monitoring and maximize production on their assets.
Al-Mutairi, Amal (Kuwait Oil Company) | Al-Haqqan, Hamad (Kuwait Oil Company) | Ren, Zu Biao (Kuwait Oil Company) | Tinnin, John (Baker Hughes Inc.) | Randazzo, Santi (Baker Hughes Inc.) | Pare, Antoine (Baker Hughes Inc.)
Kuwait Oil Company conducted a 4DVSP steam flood monitoring program in a heavy oil field to help optimize development options. The baseline survey for this 4DVSP was acquired in January 2016 and the monitor survey was acquired in January 2017. The key objectives for this reservoir surveillance project include acquiring a repeatable baseline survey; image two vertically stacked thin reservoir units, perform characterization to understand reservoir complexity and lateral barriers, and estimate the steam chest size (sometimes referred to as a steam chamber) after 30 days of steam injection.
The 3DVSP survey took less than a week with rigless acquisition only during daylight hours. The survey area was fairly congested with infrastructure making it difficult to manoeuvre between source positions easily. To tackle this, two groups of vibrators were used with a source driven acquisition technique. This meant much of the acquisition process was automated providing better efficiency and reducing human error.
The resulting data was processed and imaged with proprietary 3DVSP Kirchhoff depth migration algorithms. Due to an innovative acquisition design, output frequencies were 30% higher than achieved in previous VSPs or seismic data in the area. Velocity models were derived using the zero offset VSP data and a geomodel was derived from well data. The migration was sampled at dX/dY/dZ values of one meter each to help create a high resolution image. Synthetic seismograms from well logs and corridor stacks from the zero offset VSP were used to accurately tie the well data to the 3DVSP volume. This data volume was mapped using seismic workstations and amplitude anomalies were obvious around the steam injected well making possible the mapping of the steam chest. Deterministic inversions from this data help identify facies changes and channels explaining the direction and pathways of the steam flow. In summary, each of the goals for this project was achieved. The two thin reservoir units and the top sealing shale were resolved while inversions were very beneficial for reservoir characterization and understanding facies changes. The steam chest was easily discernable and its volume was calculated. These results justified the first ever 4DVSP in Kuwait which was acquired in January 2017. Ultimately, knowing where the steam fronts travel, where lateral barriers divert the steam, and how quickly it moves will help to optimize the development plans for the best possible EOR effectiveness and recovery rate improvement.
During steam assisted gravity drainage (SAGD) processing of an oil sands reservoir, two marked phase changes occur. First, bitumen itself changes from quasi-solid to liquid when heated. Second, a steam chamber develops as the liquid bitumen is displaced with steam during production. Therefore, steam chamber development is a direct indication of production performance. A good understanding of the developed chamber extent and future chamber growth is essential for a successful SAGD project. In this paper, we present an integrated approach to quantitatively predict chamber geometry, fluid saturation and temperature. We define the chamber in three classes, based on phase changes: (1) developed steam chamber zone (high steam saturation and temperature, indicating completed production); (2) mixed fluids zone (low steam saturation and high temperature, indicating near-future production); and, (3) transition zone between quasi-solid to liquid (warmed reservoir with future potential),
The above workflow was applied to the Nexen Long Lake SAGD project using the 2002 baseline and 2014 monitor seismic data. The developed steam chamber (class 1) was predicted for 2014. The 2014 monitor data were also used to predict the future extent of the developed chamber for the year 2016 (using classes 1 and 2). The predicted chambers for both 2014 and 2016 were found to correlate well with production data.
Presentation Date: Thursday, September 28, 2017
Start Time: 11:25 AM
Presentation Type: ORAL
Heavy oil reservoir monitoring is a challenging topic, which is of significant value for thermal production. The injected hot steam can drastically affect the reservoir's properties by reducing oil viscosity, which will further leads to velocity and impedance change. The drop in impedance can cause abnormally strong reflections on the top of steam chamber. In addition, the mixture of steam, oil, and water inside the steam chamber can cause strong dispersion and intense attenuation of seismic energy, resulting in obvious anomaly in frequency domain.
In this paper, we show the velocity and impedance changes of oil sands before and after steam injection by lab measurements. Then by extracting the seismic attributes of both the baseline and monitorline seismic profiles, we analyzed the differences between them and found that several seismic attributes are very effective in detecting the steam chamber. These attributes either reflect the strong reflections caused by extremely low impedance of steam chamber or reveal the intense energy attenuation inside the steam chambe caused by the pore fluid mixture.
Presentation Date: Thursday, September 28, 2017
Start Time: 10:35 AM
Presentation Type: ORAL
Sudakov, V. (Kazan Federal University) | Nurgaliev, D. (Kazan Federal University) | Khasanov, D. (Kazan Federal University) | Stepanov, A. (Kazan Federal University) | Khamidullina, G. (Kazan Federal University) | Kosarev, V. (Kazan Federal University) | Galukhin, A. (Kazan Federal University) | Usmanov, S. (Kazan Federal University) | Zaripov, A. (JSC Tatneft) | Amerkhanov, M. (JSC Tatneft)
The pdf file of this paper is in Russian.
Currently the super-viscous oil deposits are under active development in the Republic of Tatarstan. The general method of production is Steam-Assisted Gravity Drainage (SAGD).
The problem of creation the complex of methods to monitor and control the reservoir processes caused by steam injection is of a great importance for increasing the development efficiency.
Traditional control methods of shallow deposits development are normally based on seismic survey and whether insufficiently adatped for shallow deposits of super-viscous oil or very expensive. Thus, the special modifications of geophysical methods are required.
The paper discusses general approaches used for creation of complex of methods for steam chamber monitoring the oil production from the shallow deposits of super-viscous oil by SAGD. The methods developed include seismic and geoelectric survey.
In context of integrated monitoring technique creation the set of special core survey was conducted to define the possibility of detection of the steam chamber distribution by seismic methods. The distinguishing feature of the monitoring technology developed is the use of downhole monitoring tools to receive the seismic signal and to perform the geoelectrical field establishing.
The article contains the description of the seismic data obtained processing methods and the results of the seismic data interpretation.
The study was made with the financial support of Ministry of Education and Science of the Russian Federation (project ? ?02.G25.31.0170)
In Steam-Assisted Gravity Drainage (SAGD) fields, monitoring steam chamber development is important for identifying produced and bypassed pay, and optimizing production performance. In this study, we use the Jackfish-1 SAGD field to demonstrate how to integrate time-lapse multi-component seismic, well logs and production data to detect steam chamber development. The workflow involves five steps: 1) Forward modeling to link the pressure, saturation and temperature changes caused by production to seismic elastic responses, 2) 4D calibration to ensure the 4D inversion reflects production-related amplitude anomalies, 3) PS-PP registration to register PS data in PP time, 4) Time-lapse PP-PS joint inversion to provide Vp, Vs, and density estimations for monitor, baseline and their associated difference volumes in three dimensions, 5) Mapping steam chamber and predicting future production. The developed steam chamber, which was estimated using increases in Vp/Vs ratio and decreases in P-impedance, shows a good match with observation wells and cumulative oil produced. Mobile bitumen, implying future production, was delineated via a S-impedance decrease and Vp/Vs ratio increase due to the shear velocity reduction during a phase change from a quasi-solid to liquid. Finally, we integrate results from 3D baseline facies & fluids classification and 4D studies to determine future potential, to identify bypassed pay, and serve as a guide for optimizing production performance in the future.
Presentation Date: Wednesday, October 19, 2016
Start Time: 3:35:00 PM
Presentation Type: ORAL