The expertise of GLJ’s professional team extends beyond the world of reservoir evaluations; our engineers and geoscientists come from a richly diverse set of technical backgrounds and have incomparable understanding and experience in the petroleum industry. Recognized as a technical authority throughout the industry, GLJ is regularly commissioned to lend its expertise in technical studies of a variety of different types to provide the detailed knowledge and insight required to make truly well informed decisions.
Our unique ability to house data intensive simulations and sensitive information on our native servers on a plethora of software suites allows us the flexibility to meet nearly any technical challenge head on.
The tool chosen to analyze reservoir performance depends upon the availability of data, amount of time allotted and accuracy of outcome required, and can range from simple analogy methods to full field simulation. Simulation studies require a significant amount of data and preparation, builds upon classical reservoir engineering approaches and involves all of the other methods of static reservoir engineering analysis. A simulation model often reveals important connectivity issues and lack of complexity in the geologic model.
An advantage of building a reservoir simulation model is that it adds the elements of space and time into all calculations. Typically time dependent data, such as varying production and injection data, is handled more rigorously than in traditional analyses. The final results are fairly detailed and a high degree of confidence can be achieved from the model’s abilities to match pool history and predict future performance.
GLJ has extensive experience in developing and reviewing reservoir simulation models on behalf of our clients, and the direct application of simulation results to reserves reporting. Deterministic simulation models may provide optimistic forecasts due to an inherent understatement of reservoir heterogeneity in the geological model and as such, they are generally used to support reserves values in the higher risk categories, such as proved plus probable and proved plus probable plus possible.
Our reservoir simulation team commonly utilizes Eclipse, CMG (Imex and Stars) and Terasim/Geosim/Terapro, amongst others, to develop rigorous simulation models. GLJ’s team has significant expertise and experience with developing complex reservoir simulation models including:
- Heavy oil, thermal, SAGD models
- Coalbed methane reservoirs
- Tight formations
- Weakly consolidated or unconsolidated sands
- Geomechanical operations
- Naturally fractured systems
- Multi-stage fracturing in horizontal wells
- Compacting formations
Reservoir simulation studies are an integral part of analyzing and forecasting performance of oil and gas reservoirs and particularly as a guide in field development optimizations.
Consistently accurate and reliable solutions to petroleum resource problems require a solid understanding of the extent, thickness, discontinuities and physical properties of the reservoir in question. GLJ’s knowledgeable geophysicists, geologists and petrophysicists have the experience, skills and software to develop the most accurate possible reservoir picture.
This core group of professionals act as a resource within GLJ’s interdisciplinary teams, providing solutions to complex resource exploitation and exploration problems. Working closely with GLJ engineers, the geosciences team generates a three-dimensional reservoir picture as well as its structural and volume configuration, which supports GLJ’s reserves evaluations and resource appraisals. A key element of GLJ’s geological and geophysical analysis is quantifying and communicating the risk and uncertainties associated with interpretations.
In addition to supporting technical studies and evaluations, GLJ’s geosciences group provides in-depth and stand-alone petrophysical, geological and geophysical services.
Geological Services include:
- Petrophysical studies
- Regional geological studies
- Geological mapping including complex faulted and unconventional tight/shale reservoirs
- Exploration prospect generation
- Geostatistical modeling
- Probabilistic multi-mineral petrophysical solutions for complex shale reservoirs
- Resource fairway identification
- Exploration risk assessments at the prospect, play and portfolio level
- Basin resource potential studies
- Ultimate potential and supply studies
Geophysical Services include:
- Seismic processing / reprocessing
- Well log calibration to seismic data
- Advanced 3D visualization
- Seismic attribute and seismic inversion analysis
- Audits of seismic interpretations prepared by others
- Creation and inclusion of seismic synthetics
- Integrated 2D / multiple 3D interpretation
- Complex structural mapping
- Seismic stratigraphy
- Geophysical analysis can be performed using SeisWare, Kingdom, and Petrel
GLJ’s team of professional geoscientists have extensive experience, having conducted studies in more than 40 countries and 60 basins worldwide.
Flowing Material Balance (FMB) or Dynamic Data Analysis (DDA) is a useful tool in the modern reservoir engineers’ tool box. This tool uses pressure, production and geological information to quickly generate graphical solutions with diagnostic plots. The data requirements are far less than full-field simulation models, so results can be generated in a matter of hours instead of weeks. GLJ has been utilizing FMB in evaluations of domestic and international reservoirs for more than a decade.
FMB analysis can be applied to both conventional and unconventional resource evaluations. Often, these techniques can be applied where more traditional forecasting techniques such as decline curve analysis, are difficult to conduct. Often, the true production potential of the well is masked and difficult to assess using standard engineering tools. The graphical solutions as provided through FMB analysis can lead to more accurate analysis of these situations.
Using FMB can also lead to other important reservoir information such as:
- Reservoir energy or estimates of volumes-in-place
- Reservoir characteristics (permeability, shape, fracture half length, effective skin factor)
- Interference effects
One of the most valuable pieces of information that can be provided by FMB analysis is the amount of energy that has been seen by the well, platform or field. Forecast scenarios can be constructed to help determine the range of recovery factors that are reasonable with the information to date. This information is commonly used to help plan future drilling locations, identify development opportunities and optimize drilling density.
Gas storage studies have been an integral part of GLJ’s portfolio for many years, with scopes ranging from evaluating long established gas cycling schemes to assessing the feasibility of converting old, abandoned oil pools to accommodate gas storage. Multi-disciplinary techniques have been utilized which include engineering, geological and geophysical tools to assist in gas storage studies. Analysis techniques commonly utilized in gas storage studies include:
- Material balance techniques
- Reservoir simulation models
- History matching, sharing and allocation models
- Optimization studies
The following are a few prominent gas storage studies projects where GLJ as conducted:
- Multiple, interacting pools such as those of Tecumseh/Chatham in Ontario for Enbridge/Union have been assessed by material balance approaches and straight line slope methods to quantify meter losses, migration losses and gas LUF (Lost and Un-accounted For).
- Several long standing gas storage pools in Saskatchewan were analyzed using simulation models to optimize gas storage capacity, maximize withdrawal rates by strategically drilling new vertical or horizontal wells and to help determine gas allocation among individual wells.
- The abandoned Amposta oil field offshore Spain was studied by a comprehensive reservoir simulation model to assess the viability of converting it into a cyclic gas storage pool.
GLJ prepares gas, oil or bitumen supply studies to support infrastructure projects including pipeline and facilities construction or optimization. Petroleum supplies must be well understood in order to determine the economic viability of pipelines or facilities that generally have a 25 year life. Our services range from basin wide resource potential studies to reserves and resources for regions within the connection area of the proposed pipeline or facility. GLJ estimates the petroleum recovery potential and prepare production forecasts for the existing and planned drilling and development programs within the area of interest.
The following are a few prominent projects where GLJ has provided gas, oil or bitumen supply studies:
- Gas supply study for the Mackenzie Delta and offshore Beaufort Sea to support the Mackenzie Gas Project in Northern Canada for Imperial Oil Resources Ventures Limited. The study included both contingent and prospective resources.
- Reserves and supply assessment of gas under contract to Pan-Alberta Gas Ltd. The analysis was conducted on over 200 companies and 1100 contracts in Alberta.
- Deliverability Report prepared for Maritimes & Northeast Pipeline Management Ltd. to demonstrate the existence of sufficient reserves and deliverability to maintain natural gas throughput on their pipeline system. Primary gas sources included the Sable Offshore Energy Project and the Deep Panuke Field, both located offshore Nova Scotia.