The Future of the Fuel and Energy Complex: Latest Technologies and Developments in the Oil and Gas Industry

What IT solutions are used in the fuel and energy complex, what is “smart” water, why nanoparticles from ash are used for oil production, and how bacteria help to produce gas from coal, Trends were discussed

IT developments to help geologists

Oil and gas production is a science-intensive field, so cutting-edge technologies are indispensable here.

There are two types of data obtained about the reservoir:

• straight lines – cuttings (tiny rock samples that are brought to the surface during drilling), core (rock samples with a diameter of 5-10 cm, which are also specially sawn during drilling), fluids (liquids and gases from the reservoir);
• indirect – seismic data, or geophysical surveys of wells.

One of the most modern and effective reservoir study technologies is detailed cuttings analysis. Detailed sludge analysis is a study of what minerals and elements the sludge is made of. Since cuttings are small pieces of drilled rock, their studies make it possible to understand how the reservoir is represented: what rocks and fluids, and even what elements of the Mendeleev system it consists of. The latest techniques, equipment and software can perform this procedure directly in the well itself during drilling.

By combining geophysics, cuttings and core data, geologists get very detailed information about the object. By themselves, these datasets are widely used both in further drilling of wells and in order to increase production.

Each drilled well is just a point in the reservoir area. What is between these points, no one knows. In order to understand what is between these points, 3D seismic is used: geophysical studies of reflection from artificial seismic waves from layers.

Modern IT-developments and techniques allow for the quantitative interpretation of 3D seismic. To do this, data on core, cuttings, geophysics and 3D seismic are combined. As a result, an approximate idea of ​​the porosity and saturation of the reservoirs is obtained. The resulting set of data allows you to build as accurate a digital 3D reservoir model as possible. The software is capable of simulating the physical processes of fluid movement, stress changes and formation deformation on such 3D models, adapting these processes to real field data (measurements of production, pressures, field studies).

There are a number of technologies, methods and equipment that perform the above operations and are improved every year, automated, and even begin to “think” themselves through machine or deep learning, thereby eliminating the possibility of error due to the human factor.

Modern powerful computers and specialized software are capable of transferring a real layer into a digital “double” (3D model) and then carrying out all the necessary operations and research on this model. For example, to understand where to drill production and injection wells, what and in what volumes to pump, which wells to treat with acid, chemicals, where and how to conduct hydraulic fracturing.

Moreover, there can be an infinite number of options for these operations on a 3D model, with minimal costs. And to check everything on a real layer, much more money is required.

Smart Solutions for Unconventional Reservoirs

Reservoirs are rocks that have the ability to contain oil, gas and water and release them during development. Unconventional reservoirs are called very low permeability reservoirs: these are shale or tight rocks containing oil and gas mainly in natural fractures. The vast majority of production from such reservoirs is carried out in the United States, where various technologies are being developed for hydraulic fracturing – the main way to force oil and gas to flow to the well.

In a horizontal well with a length of 1,6–3,2 km, multi-stage hydraulic fracturing (MSHF) is carried out, where the distance between stages is 50–100 m. and water) begin to flow to the well.

A horizontal well is a subspecies of wells in which the wellbore in a productive (oil or gas reservoir) is drilled at an angle of at least 80 degrees to the vertical. Due to the fact that the layers are located mainly horizontally, then drilling wells in these layers horizontally is the most rational, because. allows you to get more.

It often happens that a horizontal formation is separated by horizontal impermeable interlayers (eg clay). As a result, a kind of cake is obtained from interlayers of a productive reservoir and impermeable reservoirs. In this case, if a horizontal well is drilled, it will pass through only one of the productive interlayers. To produce oil or gas from all interlayers, hydraulic fracturing is carried out. Multi-stage hydraulic fracturing is a subspecies of hydraulic fracturing, which is carried out in horizontal wells, in several places along a horizontal wellbore. Each such place is called a stage.

The cost of multi-stage hydraulic fracturing at one well is $2-6 million, so the optimization of such work is the most important task. The MSHF process proceeds as follows:

• fluid is pumped into the well, which breaks the rock;
• then proppant (mainly sand) is pumped into the fractures. Water is pushed further into the reservoir. The proppant is pumped into the reservoir in suspension in the liquid. This fluid pushes the fracturing fluid previously injected into the formation;
• sensors measure the injection pressure throughout the entire process.

The proppant is needed to keep the formation from closing. If it is not injected, then the rock pressure, which averages 500-800 atmospheres for such formations (for comparison, the division is 1 atmosphere on the earth’s surface), will simply close the cracks. But the proppant is sand through which oil flows quietly (if liquid is poured into the sand on the beach, it will saturate it, as well as in the reservoir).

Expensive microseismic is often used to identify fractures. However, modern “smart” solutions using special mathematical algorithms and machine learning can do without it.

Fracture identification is needed to understand why one well produced more oil than another, and to properly design hydraulic fracturing.

Nanotechnologies in the oil and gas industry

Nanotechnology refers to all technologies in which processes occur at the micro level, leading to a result at the macro level.

Oil and gas occur in the pores of the rocks. Imagine a stone: if you drop water on it, it will be saturated and the water will be in the pores of the stone. In the same way, fluids occur in the pores of rocks.

One of the most interesting technologies is the injection of a mixture of water with nanoparticles into oil and gas reservoirs, which change the properties of the rock and/or injected water. In some cases, certain chemicals are added to the injected solution to speed up the processes. As a result, such a solution makes it possible to better wash oil from the pore surface and displace it to production wells.

There are a huge number of varieties of nanoparticles, but engineers mostly try to choose inexpensive ones. I participated in the development of technology for the use of nanoparticles from wood and coal ash, as well as ash from the combustion of various products in enterprises. Particles of such ash or ash are smaller than the pore channels, which allows them to penetrate deep into the formation. The results showed very high efficiency, comparable to expensive nanoparticles. Similar solutions are applied in drilling, when nanoparticles prevent the drilling fluid from penetrating into porous rocks.

Modern laboratory equipment is capable of studying at the micro- and nanoscale the physical and chemical processes occurring between the rock, the fluids that saturate it, and the fluids injected through the wells. One of the modern technologies in which these processes are preliminary studied is the injection of “smart” water. For its production, the most optimal composition of salts dissolved in water is selected. This allows, when “smart” water is injected into the reservoir due to various ion-exchange processes occurring between the salts of the injected and reservoir waters, as well as rock particles, to wash more oil out of the reservoir or block the areas from which water flows.

Technologies using waves of various frequencies, including magnetic and ultrasonic, have become widespread. The mechanism of action works due to the physical action at the micro- and nanolevels on rock particles and fluids. For example, to remove deposits of paraffins, asphaltenes, resins, calcium carbonate in pipes through which oil is then pumped, special devices are used that, due to shock-resonant frequencies, break up the molecules of deposits. Gradually, sediment particles are separated from the pipe walls and carried away by the flow. Another example is the special ultrasonic tools that are lowered into wells, which also clean pipes and perforations from deposits of various types. A kind of “shake” allows the particles to separate from the surface on which they are stuck, and the flow rate (throughput) of the well increases.

“Green” technologies in the field of oil and gas

In recent years, oil and gas companies have been actively implementing various technical solutions for generating solar, wind, gravity, hydrothermal electricity at their facilities, as well as storage systems for this electricity. In connection with the development of electric vehicles, most oil and gas companies are equipping their gas stations with modules for charging electric vehicles.

I happened to be involved in the development of organic liquid redox batteries used for industrial energy storage. Redox batteries are a type of rechargeable liquid battery that uses ions of various chemical elements in various oxidation states to store chemical potential energy.

It is noteworthy that the electrolyte selected for such systems is made from products of deep oil refining, and industrial oil and gas facilities that were previously built and are not currently used due to well depletion can be used as electrolyte storage and pumping tanks. A small fleet of such storage facilities can provide electricity to a medium-sized city.

The “green” technologies in the oil and gas sector also include:

• injection into wells of waste from industrial enterprises, including chemical plants, power plants. Tailored to certain reservoir conditions, the injection of such wastes, on the one hand, works as a method of increasing oil recovery, on the other hand, as a way to combat environmental pollution through waste disposal;
• the use of associated petroleum gas, which is released from oil when it is lifted from the bottom of the well to the wellhead, is also a “green” solution. Such gas is used to generate electricity, heat industrial facilities, and is often processed into consumer products. In some cases, if there is too much of it, it is injected back into the reservoir as a method of enhanced oil recovery;
• widespread microbiological exposure technology is also categorized as “green”. Certain bacteria and/or nutrients (food for bacteria) are pumped into the reservoir, which allow better washing of oil, or block the flow of formation water into the wells;
• even more advanced technologies involve genetically modifying bacteria to produce gas from coal. Wells open not only oil, gas or aquifers, sometimes coal ones also come across. The injection of such bacteria into coal seams with the presence of water leads to the fact that microorganisms eat coal, and methane is the product of their vital activity, which is then extracted from the same wells.

These methods are considered environmentally friendly, since the extraction of hydrocarbons is obtained using biotechnology. In fact, this is not direct production in the traditional sense, but passed through bacteria. In addition, the use of bacteria makes it possible to replace expensive traditional technologies and save resources.