Research Projects of All Chairs
Innovative Coring Concept for Exploration Drilling Drilling
Among the industry, is currently accepted that improper retrieval schedule of the core from bottom to the surface can result in either slow tripping speeds or the detrimental irreversible core damage due to the creation of microfractures.
The latter which is well-known as the gas-expansion core damage, is in reality worse as the core is not representative of the formation. In either case, high costs are incurred to the operators.
The primary aim of the project is to understand the mechanism of creation of the gas-expansion induced microfractures. To accomplish this, the essential macro and micro models are developed. In addition, using the results of the models, the core tripping process will be optimized based on the affecting factors including the core lithology, rock and fluid properties, etc.
Analysis of Drill String Dynamic Behavior
Vibrations are caused by bit and drill string interaction with formations under certain drilling conditions. They are known as destructive loads and thus are leading to downhole fatigue failures, severe bottom hole assembly and bit wear and may cause wellbore instabilities. Vibrations are affected by different parameters such as weight on bit, rotary speed, mud properties, bottom hole assembly and bit design as well as formation characteristics.
In this work the relationship between formation characteristics and drill string vibrations in a laboratory scale have been studied. Non-linear models have also been built to establish a relationship between different parameters. A fully automated laboratory scale drilling rig, the CDC miniRig, was used to conduct experimental tests. A vibration sensor sub attached to the drill string, above the bit, recorded the drill string vibrations during the tests and additional sensors recorded the drilling parameters.
It is concluded that the formations can be recognized in real-time by analyzing vibration measurements. This allows to differentiate individual layers with different strengths.
CFD Analysis of Gas Kick Scenarios
A gas-kick is a fundamentally transient event accompanied by many unknowns. Common approaches in kick modeling are based on the assumption of a more or less single “gas bubble” present in the annulus and slowly migrating upwards after shut-in. While this assumption satisfies straightforward volumetric well control aspects, it ignores species transport and chemical reaction kinetics leading to drill string corrosion.
The intention in this project was to make no a-priory assumptions regarding the evolving flow field. Instead focus was put on a spatially highly resolved model covering the near bottom-hole section of the wellbore where two-phase interactions could be observed at a close-up view.
The project illustrates the value of CFD simulations to verify flow conditions and to support the design process of new measurement tools for early kick detection.
Real Time Downhole Kick Detection
Around the globe, every day several hundreds of oil and gas wells are being drilled. All these wells face different challenges but have one thing in common. They all have the potential for well control incidents which can affect the crew, the rig and the environment. This project aims to develop a downhole sensor package which allows kick detection in real time utilizing high speed telemetry systems. This will significantly reduce the reaction time on well control events.
In this project, high sensitivity sensors will be evaluated for downhole kick detection. Influencing parameters such as cutting size and distribution, temperature and vibration effects among other variables affecting the sensor performance will be investigated. Based on the initial evaluation, using CFD modelling, an optimized prototype of a sensor package will be designed and tested.
Real Time Wellbore Instability Detection using Ultrasonic
Drilling programs continue to push into new and more complex environments. As a result, accurate measurements of drilling data in real time are becoming more critical by means of minimizing the risks as well as the costs. The determination of the actual wellbore shape in real-time can be considered as one of the key components to detect problems such as borehole instability.
The scope of this project was to develop an ultrasonic caliper tool for borehole geometrical measurement and developing an additional ultrasonic sensor to record the speed of sound in the drilling fluid at the desired depth. Measurements were performed in artificial wellbores with geometrical anomalies.
Numerical simulation of the measurements and comparison of the simulated results gave estimations how accurate the data was. It could be shown that anomalies can be detected with an appropriate accuracy if circle fitting methods in combination with robust error models are applied.
Surface Kick and Loss Events Detection
It is agreed that mitigating the impact of the kick and lost circulation on the drilling operation requires an efficient system, which helps to detect the kick and losses as early as possible to be able to take the necessary action on time. Continuously monitoring the drilling fluid surface and velocity inside the bell nipple might be the quickest surface measurement to detect loss and kick events.
Therefore, the main objective of this project is to develop a new concept for detecting kick and loss in the shortest possible time by using the bell nipple as a place to install the required instruments and measure the related parameters.
Long-term Cement Integrity
Justified by reported incidents, the role of wellbore cement being a competent barrier for up-hole hydrocarbon flow is questioned in many cases. In particular it is not clear whether the integrity of the bond and seal between cement and formation or cement and steel-casing is given over the life-cycle of well operations and beyond.
This research intends to find answers to possible destructive consequences of different life-time loads by studying the effects of casing micro movements, chemical interactions and corrosion and operational induced shock loads. To achieve this goal, special test procedures and equipment will be developed and experiments are to be conducted. The experimental observations will be compared to finite element / finite differences modeling results for validation.
The outcome of this research will allow to classify the risk of mature wellbores to develop integrity issues and to provide suggestions to avoid cement barriere failures.
Operations Optimization for Shale Assets
Shale gas and oil projects require large drilling campaigns: This includes drilling numerous wells continuously for a sustained production. The major change in the industry was to go from “handmade” to a “mass market” of wells. This requires an entirely different approach to optimize operations for an entire field.
This research targets exactly the optimization of all the operations by integrating all the disciplines from land, drilling, completion, production and logistics and finding the best possible way and means for this “factory” to operate efficiently.
BEER: Bio Enhanced Energy Recovery
Bio Enhanced Energy Recovery is a system developed by the Chair in cooperation with leading industry partners in Austria and Germany. BEER represents the solution on the imminent needs for environmentally conscious energy recovery methods in geothermal reservoirs. All applied components are non-hazardous and most are even used within farming and food industries.
BEER is currently undergoing the first field tests and results will become available soon. The BEER technology is based on numerous pending patents.
SCALING: Ways to Reduce Production Limitations
Scaling is one of the most problematic issues with energy production from reservoirs. Originating from hydrocarbons, formation waters, or from combinations of fluids, salts, and bacteria form barriers which reduce or stop the energy flow to the surface. Not only subsurface installations are affected, but surface installations as well.
The researchers of the Chair focus on applying physics rather than chemistry with significant success. This is not only positively influencing the production performance, it is also contributing to increased environmental care and reduced CO2 footprints.
ThermoDrill: A Novel System for Geothermal Projects
Costs of erecting wells for Deep Geothermal Applications represent a major part of the overall investment. Particularly when facing hard, crystalline rocks, the ROP becomes very low. To allow for better performance and such for easier risk assessment, an innovative technology is developed to provide much higher ROPs.
A combination of the rotary drilling technology with jetting technologies offers great opportunities for improving the drilling performance and reducing the need for fracturing.
Pump Testing Facility
Low oil prices push the demand for efficient production, especially in mature fields. Reducing the costs of artificial lifting by increasing efficiency is mandatory for extending meantime between failure, economic limit and increasing recovery factor.
For achieving these goals the Pump Testing Facility was established, to allow low risk, low cost, and high performance testing of new technologies, including various artificial lift systems. Montanuniversität Leoben constructed this facility to overcome the enormous field testing costs and to speed up innovation. The testing facility is able to test oil field equipment under conditions occurring in depths up to 500m.
As an integral part of the chair’s research programs, new technologies, self-developments and patents will be tested before being applied in fields. The pump testing facility is used to provide services to the industry and to test according to industry needs. In close cooperation with the industry, this pump testing facility will be expanded to cover more special operational modes and events that may occur in the field.
In the project we focus on the coupling of flow and geomechanics in naturally fractured reservoirs. The final goal is to model CO2 injection in fractured reservoirs with pre-existing faults and to estimate the effect of mechanics on flow and on storage capacity as well as estimating the risk of leakage and fault activation.
Underground Hydrogen Storage
Underground hydrogen storage is a promising way to store excess renewable energy with sufficient storage capacity. The Reservoir Engineering group participates in a pilot project assessing the feasibility of large-scale hydrogen storage in a depleeted gas field in Upper Austria. Our aim is to assess chemical interactions between the reservoir and the injected hydrogen/methane mixture and to simulate the injection and production processes in order to predict the quality of the backproduced gas. For the future we plan to extend the study to microbial activity and its impact on hydrogen storage and conversion operations.
Development of Low-cost EOR Methods
We develop a combined experimental/numerical workflow to provide solutions for Improved & Enhanced Oil Recovery (IOR/EOR). We aim for fundamental understanding of IOR/EOR methods across the scales (from the pore to field scale) and for solutions tailored to the development of individual fields. For this purpose we currently establish a laboratory for the investigation of interfacial properties (fluid-fluid and rock-fluid) and core flooding supported by Imaging methods such as micro and medical Computerized Tomography. In parallel we develop the numerical tools that are neeted for data interpretation and upscaling, resulting in a combined numerical/experimental workflow.
Wavelet-based Multiresolution Upscaling of Porous Media
We utilize the multiresolution framework of wavelet analysis that has been developed for image processing in order to develop a novel method for numerical upscaling of porous media flow. For this, equivalent rock properties are generated from the geologic fine-scale models via wavelet analysis making use of structured and unstructured grid representations. The wavelet method is well suited for upscaling rock properties and especially if spatially correlated heterogeneity is present. With this project we aim to significantly improve the performance of numerical upscaling with respect to accuracy and computational costs.