The RWE Dea Laboratory is situated in Wietze, a town not far from Celle in the North German state of Lower Saxony. Wietze Laboratory supports all our national and international sites with analytical examinations, investigations and surveys as well as advisory services in the fields of geoscience and production chemistry.
By undertaking geoscientific investigations of individual boreholes, our specialists can characterise in detail the properties of reservoir and source rocks. We concentrate on three fields in our geoscientific analyses at Wietze Laboratory:
Our precise petrophysical analyses and sedimentological interpretations help to determine the hydrocarbon potential of a reservoir. For this we examine conventional core samples and those taken from well walls as well as drill cuttings and material taken from surface outcrops, using sophisticated techniques such as thin section microscopy and
state-of-the-art equipment. The latter includes an X-ray diffractometer, which tells us the exact mineralogical composition of a rock, and a scanning electron microscope, which supplies us with insights into the tiniest pore spaces of a rock. With this equipment we can analyse and evaluate a depositional environment, the spatial origins of sediments and their spatial dimensions, geometry, structure, solidification over space and time, pore geometry and mineral composition. All this plays a decisive role in the optimal development of a reservoir find through the drilling of additional wells.
Palaeontologists study fossils, i.e. the embedded remains of plants or animals in rocks, to determine the age and origins of rocks – and to discover inter-relationships between different wells. Since large fossils are rarely found in our rock samples, we mainly examine microfossils. As a rule, these fossils are incredibly tiny structures such as the shells of single-cell organisms (foraminifera) and of tiny ostracods or the skeletons of other organisms. At Wietze Laboratory we examine these fossils in our search for biostratigraphic inter-relationships to determine the relative chronology of rock strata. Another of the tasks our geoscientists carry out is to analyse the prehistoric habitats and identify the various types of kerogens – the organic matter of a solid or waxy consistency that is found in sediment rocks, was formed from bacteria, decayed algae or woody material, and is the most common form of organic hydrocarbon found under the surface of the Earth. At Wietze Laboratory we determine the thermal maturity of kerogens and use this to deduce the maximum temperature the source rock was heated to. This, in turn, enables us to evaluate the rock's hydrocarbon potential.
More than 20,000 metres of core samples from all over the world – samples of cap, source or reservoir rocks – are stored in modern facilities at Wietze Laboratory. Some came from the deserts of Libya, others from the depths of the Barents Sea or the North German Plains – just around the corner, as it were. All were extracted using special core drills.
Cores are examined in our lab to discover the exact properties of the rock and take small samples for subsequent specialist examinations. We cut wafer-thin slices out of these core samples so that we can examine them under a microscope. Though these thin sections are no more than 0.03 mm thick, they show us the mineralogical composition of the rock. This enables a geologist to discover what changes affected the rock millions of years ago, which can be crucial in determining whether a rock is a suitable storage medium for oil or gas.
Our production chemistry laboratory specialists come up with an answer to any chemistry-related question that crops up in our oil and gas production and gas storage activities. And they supply our German and international sites with valuable recommendations based on their experience and the results of their measurements in
How good is the quality of the oil and gas in our reservoirs? Which drilling fluid is best suited to a particular task? What inhibitors can best prevent corrosion? These are the kind of questions we have to answer from the field of oil and gas chemistry. We conduct extensive lab experiments to select the most suitable oilfield chemicals, drilling fluids and production equipment. And we use simulation tools to determine the most suitable material and design for processing facilities and the pipes through which the oil or gas is transported.
We support our engineers in treating injection water and preventing or getting rid of corrosion or deposits of hardly soluble substances such as lime, paraffin or hydrates in well installations, pipelines and in reservoirs close to production wells. Another of our tasks is to control the amount of bacteria present in oil and gas processing facilities and injection water. In addition, we ensure optimal oil-water treatment, e.g. through selecting the right oil-water demulsifiers or removing any residual saltwater from crude oil. Quality controls on the hydrocarbons we have produced round off the range of services provided in the field of oil and gas chemistry.
Our mud laboratory is equipped with the latest equipment for controlling the quality of drilling fluids (mud) to international standards and providing general support for our drilling engineers. Drilling fluids have to be capable of transporting drill cuttings to the surface, sealing the well walls through formation of a so-called filter or mud cake, and cooling and lubricating the bit. We also support our drilling engineers by carrying out tests to determine the best combination of mud additives. A state-of-the-art high-pressure/high-temperature viscometer enables us to examine drilling fluids and their flow characteristics under realistic well conditions – up to 260° C. and 2,000 bar. We can also conduct lubricity tests to test the lubricating properties of drilling fluids. This is particularly important for lengthy highly deviated wells where a considerable amount of friction is generated.
We support oil and gas exploration and production through a variety of computer simulation tools employed day after day at Wietze Laboratory. ChemCAD, for example, is a very powerful process simulation program for complex chemical-technical procedures. We use it to evaluate in detail our pressure, volume and temperature (PVT) analyses. We also simulate in lab conditions the formation of mineral deposits and use the results to select the most suitable inhibitors for the specific purpose required. And we use our REFPROP (Reference Fluid Properties) program to calculate physical parameters in that this simulation tool determines the thermodynamic properties and transport characteristics of hydrocarbon compounds.
To extract as much oil as possible from a reservoir, our experts use a variety of methods, including thermal procedures involving the injection of steam into a reservoir to reduce the viscosity of the oil. The flooding medium used may be a gas such as carbon dioxide or nitrogen.
At Wietze Laboratory we are also working on effective EOR measures. Here, we are particularly interested in procedures involving the use of suitable chemicals as agents. They include water-soluble polymers, such as those that are also contained in food – droplets shaped like sticks or balls or wool whose viscosity and weight increase the viscosity of the water so that it flows at a greater volume through the rock. This ensures that the water can no longer take any easy path through the reservoir but flows to where the oil is located, and thus presses it out of the rock.
Our EOR Team uses lab tests to determine whether a field is suitable for tertiary recovery measures of this nature. Then our task is to select the most suitable method for a particular well. We simulate the EOR process under lab conditions and investigate the flow characteristics and flowability of fluids – at temperatures between -20° and
+300° C. In addition, we provide support in the planning and implementation of water cut-offs in oil or gas wells. With our state-of-the-art laboratory equipment we can, for example, carry out oxygen-free investigations, examine the stability of chemicals at high temperatures and pressure, and analyse whether certain fluids can be filtered or injected into a reservoir.
Wietze Laboratory employs some 35 people, most of whom work on scientific and experimental assignments. Their objective is to supply their colleagues on the operative side of the business with accurate measured data – along with a professionally sound interpretation of these data. This provides significant support for all our upstream activities.
Since a second opinion is useful in many of our projects, Wietze Laboratory also has the job of carefully checking all the quotations, tenders and services external contractors supply us with. Does a drilling fluid deliver as promised? Is the proposed corrosion inhibitor really suitable? Just two of the topics our specialist have to deal with.