Reservoir Evaluation Sampling and Testing
We are a leading oilfield consulting company. Our work spans the full spectrum of reservoir evaluation, sampling and testing services. We draw on a half-century of knowledge and experience to help our clients identify and meet their objectives. We provide optimized planning, execution and analysis while utilizing state of the art real-time monitoring and control to deploy our services globally.
Finding and producing oil and gas to meet the world’s energy needs is as challenging today as it has ever been. This trend is bound to continue as “easy” hydrocarbons are replaced by ones that are increasingly harder to find and more difficult to produce. As the complexity of equipment and services needed increase proportionately, finding the optimum combination of equipment and services needed whilst maximizing return on investment has become the biggest challenge of all. The “experience vacuum” in both the service and operator companies due to the cyclic nature of the oilfield, makes that challenge even more profound.
At REST our mission is to tackle these challenges head on and to deliver superior results for our customers.
Formation Testing and Sampling Design, Execution and Analysis
Modern formation testers are capable of collecting a massive amount of data at multiple depths, helping to describe the distribution of rock and fluid properties, define hydraulic flow units, and understand reservoir architecture. Formation tester tools are modular in the sense that that they are made up of multiple largely independent sections that could be placed almost in any position with respect to one another, depending on the application. The range of applications spans pressure and mobility profiling versus depth, fluid sampling and downhole analysis, pressure transient testing, and micro fracturing. Wireline pressure measurements continue to gain greater and greater acceptance in the industry thanks to the ability to collect large amounts of data over the entire stratigraphic sequence of interest in a short amount of time. There is thus a great deal of flexibility in these tools, but that also requires a lot of experience. Perhaps more than any other logging service, formation testing requires great deal of real-time in-situ manipulation to achieve the desired objectives. Such manipulation comes from years of experience of running formation-testing tools. This is very similar to the difference between an experienced pilot flying your plane or a rookie. In challenging circumstances which would you rather have?
The formation testing services we provide relate to the design, execution, and analysis of formation testing operations. This is detailed below.
Design is of vital importance to the operator. Without in depth analysis and prioritization of the job objectives, a clear design of the tool string is not possible, which leads to wasted time and money. Even worse, poor execution or unusable results can result in costly mistakes. In many deep water or otherwise critical projects, the cost of getting fluid data wrong can be enormous. Pre-job design includes understanding formation evaluation needs and constraints, prioritization of sampling job objectives, and design of optimal tool-string configurations and operational procedures to achieve those objectives.
The execution phase includes carrying out the following tasks in real time:
1) Monitoring and optimization of data quality and tool performance.
2) Quality control of pressure tests and gradients, downhole fluid analysis as well as pressure buildup and pressure interference test data.
3) Optimization of the job sequence including the order and duration of pressures, samples, pressure buildups, etc.
Analysis is mostly done post-job and includes pressure test and gradient analysis summary and plots, gradient and contact uncertainty analysis, pretest mobility analysis, fluid compositional analysis, and pressure transient analysis where applicable.
Cement Bond Logging and Interpretation
Cement Evaluation: Wells are cemented to provide pipe support and/or hydraulic isolation. In terms of proving support, surface casings are cemented to provide an anchor for BOPs and give support at the surface for deeper casing strings. Intermediate strings are cemented in order to isolate incompetent formations which cause excessive sloughing when not supported by casing and cement. In addition, cementing will effectively protect casing from corrosive fluids existing in sub-surface formations.
In terms of hydraulic isolation, surface casings are cemented to seal off and protect fresh water formations from being contaminated by more saline formations. Intermediate and production strings are cemented in order to seal off abnormally pressured formations, to prevent migration of hydrocarbons to thief zones, and to prevent the migration of water to perforated hydrocarbon zones. Isolation is also necessary for stimulation and injection control. Cementing evaluation is carried out to provide:
The services we provide for cement evaluation include:
Well Integrity Logging and Interpretation
Corrosion is the deterioration of metals due to interaction with its environment. Corrosion attacks every component at every stage in the life of an Oil or Gas field: from drilling platform, to production string, to storage and transportation facilities. It is estimated that costs related to corrosion are on the average 3% of all operational costs; up to 50% of these costs can be saved through proper planning.
Corrosion of tubulars in a well cannot be totally prevented, but the rate of corrosion can be controlled and minimized through equipment design, material selection, and use of protective measures such as inhibitors, coatings, and cathodic protection. Corrosion monitoring is useful to:
The services we provide for corrosion evaluation include:
Review of corrosion logging plans for traditional multi-finger caliper tools as well as ultra-sonic and electromagnetic tools.
Production Logging and Interpretation
Production logging helps provide flow patterns of well fluids under dynamic production or injection conditions. In producing wells, production logs can determine which perforated zones are producing fluids, ascertain the types and proportions of the fluids, measure the downhole conditions of temperature and pressure, and the rates at which the fluids are flowing. Production logs are also used to detect mechanical problems in producing or injection wells and to provide guidance for workover in such wells.
A suite of production logging tools is available in different configurations and sizes and can be run either on electric line, slick line, fiber optic line, or coil tubing. Data can be collected in either real time surface read out mode or in recorded mode. The four basic sensors common in any production logging string include temperature, pressure, fluid density, and flow rate measurements. Other more specialized sensors can be added to enhance the representation of the logs or to overcome a special situation or a certain problem. Hold-up meters, noise, nuclear density, and radioactive tracers are classical examples. Multiphase flow regimes in highly deviated and horizontal wells are fundamentally different from that encountered in vertical wells. In such wells, identification of complex fluid entries and detection of fluid re-circulation requires the use of imaging tools. These tools use resistivity, conductivity, refractive index, neutron interactions, or micro-spinners to profile the holdup and/or velocity profiles across the wellbore.
The services we provide for production logging include:
Reservoir Saturation Monitoring
Reservoir Saturation measurements track reservoir depletion over time and are crucial inputs for the development of workover and enhanced recovery studies and for the diagnosis of water- related production problems such as injection-water breakthrough. There are essentially two ways to perform a reservoir evaluation and monitor saturation through casing. The first measures the decay of thermal neutron populations and the other determines the relative proportions of carbon and oxygen in the formation using pulsed neutron inelastic gamma ray spectroscopy. The salinity of formation water determines which of these methods is appropriate for any particular well. Chlorine, which is abundant in saline water, has a large neutron capture cross section, and its presence is readily established using the pulsed neutron decay logging technique.
However, in wells where formation water salinity is low, variable, or unknown, the pulsed neutron spectroscopy (also called the carbon/oxygen method) is often used. The two methods may also be combined if there are too many unknowns. The logs are often run in time-lapse mode to be able to track fluid contact movements and understand the dynamic behavior of the reservoir. The services we provide for reservoir saturation monitoring include:
Well Testing Design, Execution, and Analysis
Well tests may be conducted at all stages of the life of a reservoir from exploration through development stage as well as in producing or injection wells. The objectives at each stage range from the simple measurement of the reservoir pressure to the complex characterization of reservoir features. Most pressure transient tests can be broadly classified as either descriptive reservoir tests or single well productivity tests.
Descriptive reservoir tests are conducted to:
Assess reservoir extent and geometry.
Productivity tests on the other hand are conducted to:
Similar to formation testing, we provide design, execution, and analysis of well testing operations. The objectives are usually to obtain/evaluate one of more of the parameters below:
Well Site Log Witnessing and Quality Control
We are available to witness all types of open and cased-hole wire line logging services. We are available to be physically present at your well site 24 hours a day, 7 days a week.
Remote Log Witnessing and Quality Control
We are available to witness all types of open and cased-hole wire line logging services. We are available 24 hours a day, 7 days a week. The use of this service requires a remote, web-based data transmission system.
About Us
With a combined oilfield experience of 50+ years, our numerous assignments have taken us around the globe from North America, to the Middle East and South East Asia. Depending on the job at hand, we either work together as a team or individually to accommodate a greater workload.
Our diverse global, and cross-cultural experience, allows us to provide valuable insights to our clients’ demanding circumstances. We are well known for our ability to rapidly adapt to changing client needs, to think outside the box, and to solve difficult problems with innovative ideas. Our trademark is our tenacity for achieving stretch targets and our fit-for purpose problem solving. We pride ourselves on having a strong sense of accountability and responsibility. First and foremost, we aim to create a win-win situation with all our clients by enhancing the value added to the projects we accept.
We provide oilfield consulting services that bring immediate impact.