| Environment Safety

Q: What is the nature of the chemicals to be mixed (i. e. corrosive, flammable)?
A: One of the chemicals, ammonium nitrate, needs to be handled appropriately when in dry state. Safe practices to handle it are well known because its most common use is as AN agricultural fertilizer. One option is to dissolve it in water before transporting it to the site of the well, which makes it safe, or dissolve it on site but handle it with proper precautions until it is dissolved in water. We also use a relatively small amount of strong acids (such as hydrochloric acid), which need to be handled with proper care.

Q: Does the chemical require special mixing tanks?
A: No, simple inexpensive plastic tanks can be used.

Q: Are these chemicals harmful for the environment?
A: Worldwide track records prove no negative environment effects, no damages or accidents.

Q: Are these chemicals dangerous for the health?
A: All Chemicals are non-hazardous, eco-friendly and can be applied with bare hands.

| Technical

Q: How we differentiate hard/impermeable rocks from soft/permeable rocks?
A: The treatment of the well is customized based on the permeability of the rocks (among other factors). Generally, fast combustion (minutes) version of the method that creates pulses of high pressure is used for low permeability rocks because fracturing needs to be achieved. The rocks with permeability less than 50 millidarcy are considered low permeable (for the purposes of the method). Conversely, highly permeable rocks (over 500 millidarcy), are treated via slow combustion version of the method. For intermediate permeability, we use a combination of the above approaches.

Q: How pressure is contained?
A: The wells treated so far were at least 500 meters deep (or more). In such cases, the water pressure (the well is topped up with water during treatment) is sufficient to contain the pressure of gases generated during combustion and no additional sealing is needed — the pressure valves can be open although they do not necessarily have to be. In the future, if there is a need to extend the applicability of the method to wells of shallower depths, there might arise the need for additional sealing during treatment. However, since most of the pressure is very quickly absorbed by the deformation of the rock, even 500 meters limit may turn out to be too conservative.

Regardless of what assumptions one uses to calculate and/or estimate the bottom hole pressures, the actual results are that in none of the wells treated by the method, was there a significant pressure-induced reflux of water during the treatment, even in the cases where the fastest-combustion (i. e. producing intense pressure pulse) version of the method was used.

Q: Water cut reduced from 80% to 20% — how was this achieved? Where did the water go?
A: Water is reduced because it reacts with treatment mix to release hydrogen and other gases, which, in turn, block some of the pores in the rock containing water. Conversely, the pores containing oil are «unplugged» due to «in situ» cracking of heavy fractions (paraffins) and overall reduction of viscosity.

Q: Has this technology been tried in horizontal wells?
A: The method has been only once tried in horizontal well but we have developed plans regarding adapting it to such wells. Adjustments would be made based on well sloping, etc., and may include rubber extensions (to burn out during reaction), and other steps.

Q: Has this technology been tried in carbonate wells?
A: Yes, last year we have received very good results in carbonate wells in Russia and Turkmenistan.

Q: The distance from the nearest water-bearing horizon (300 — 500m) — There are cases here in the Middle East where long horizontal wells are drilled into thin oil rims. These oil rims are pressure supported by sea water injector wells. The distance between the wellbore to the oil/water contact could be as low as 3m. How will this affect the TBC technology?
A: Large water bodies like underground lakes or rivers are an issue if they are too close. One risk typically is flooding of well from those sources of there are large/long cracks. The injected water is not an issue.

Definition from dictionary: In petroleum engineering, an oil rim field is an oil field with a relatively thin oil zone below a gas cap. At the edges of the reservoir there will usually be an area where the top of the reservoir is below the gas/oil contact, thus forming a «rim» containing only oil, with no overlying gas.

Q: Does TBC treatment damage casing or cement bonding/integrity in the well?
A: TBC technology has been used to treat some thirty oil and gas wells, most of which kept producing at increased rate for years after the treatment. There is no evidence of damage to the casing or cement bonding/integrity.

Note: One of the clients, Surgutneftegas Company, has requested test well treatment where they recorded cement bonding and caliper logs before and after TBC treatment. Surgutneftegas reported that there were no changes before and after TBC treatment of test well. As a result, Surgutneftegas proceeded with treating several of their producing wells. Unfortunately, we do not have the actual cement bonding and caliper logs that Surgutneftegas recorded because they did not release the recorded data to us. (Surgutneftegas is a private, for-profit company and consider all its data private).

Q: Is TBC method applicable to pressure-depleted reservoirs?
A: The method typically causes increase in reservoir pressure that appear to be sustained over the long term due to continuing low-rate chemical reactions in the productive zone.

Q: How much gas is generated via treatment and what are effects on reservoir pressure?
A: Gas is generated via at least four different mechanisms.

1) TBC method generates gases via combustion of reagent mix pumped into the well. On average, about 1 ton of such mix is used per well. Each kilogram of the mix directly generates about 0.7 cubic meters of gases (if measured under normal conditions) for a total of about 700 cubic meters of gases per treatment.

2) The cracking of heavier hydrocarbon fractions in the reservoir (via catalyzed reaction of heavy oil/paraffins with hydrogen generated by the treatment) yields gaseous products, such as methane, ethane, and propane. The amount of such products varies depending on the composition of the oil.3) TBC treatment disrupts clathrate compounds. This includes gas clathrates (e. g. methane, ethane, ethylene, propylene and other hydrates) which, when disrupted, release gases into the reservoir. The amount varies based on the levels and composition of clathrates in a particular reservoir.

4) TBC treatment initiates self-sustaining catalytic cascade, which does not consume the reagents pumped into the well. This cascade involves heavy fractions/paraffins (lighter fractions do not significantly react) and water via reactions of catalytic/thermal decomposition/cracking/pyrolysis, and yields a number of gaseous products and intermediates including methane, ethane, ethylene, carbon oxides and others. This cascade is self-sustaining at low rate and continues for months to years, which is likely to accounts for the observed long-term increase in hydrocarbon production after treatment (in many cases output is increased for over 3 years) even in pressure-depleted wells (without any other measures to increase reservoir pressure)

Q: What are advantages of TBC over stress fracking & propellant combustion method?
A: We do not yet have the cost information on stress fracking+propellant combustion method but TBC treatment is unlikely to be significantly more expensive and may actually be cheaper. More importantly, TBC would typically produce greater and much more sustained post-treatment increase in oil production, making the costs per unit of additional production substantially lower. Furthermore, considering that TBC reduces oil viscosity, cracks heavy fractions, disrupts clathrates, reduces visco-skin effect/oil-to-rock binding, etc., the maximum attainable degree (i. e. completeness) of recovery is considerably greater for TBC than for other methods, including stress fracking+propellant combustion.

Q: Is there a pump rate requirement for pumping the treatment?
A: The standard, pumping equipment commonly used for well servicing (e. g. for pumping cementing solutions, washing, etc.) is sufficient and can be used at typical rates.

Q: Has this treatment been pumped in Coiled Tubing before? If not, are there any limitations of doing so?
A: No. Coiled tubing is not optimal but can most likely be used when necessary, e. g. in horizontal wells. The key is the ability to pump into the target areas, such as perforation zone, bottom hole/sump, etc.

Q: What are the chemicals required?
A: Macro-reagents are common multi-use chemicals (e. g. common fertilizers, acids, etc.) available locally in most countries/regions.

Q: Is the TCG method targeting the Matrix part only or the focus goes even beyond the Matrix?
A: The treatment can go substantially beyond the matrix. How far depends on rock permeability, new fracture formation, the variant of the treatment used, etc.

Q: In terms of quantity per foot of pay zone? What would be an optimum quantity per foot?
A: We assume this means quantity of treatment solutions. This depends on the variant of treatment selected for a particular reservoir. Generally the volume of treatment solutions increases with the size of the perforated zone. However, the volume of each treatment solution (there may be up to 3 different ones) generally does not exceed 1-1.5 cubic meters.

Q: In terms of uniform coverage, is the TBC treatment pumped together with diverters to uniform coverage of the pay zone, what type of diverters is used?
A: There is no need for diverters to achieve uniformity because the primary «working body» during treatment is gaseous (in the gas phase), which ensures sufficiently uniform distribution.

Q: Is our method changing the wettability of the rock? Does it influence the oil?
A: Regarding the rock: yes, the reactions, taking place inside the formation, change surface properties of the rock, particularly decreasing oil wettability of the rock within the channels and fractions of bottomhole zone.

Regarding the oil: The reactions influence oil, but mainly within the well bottom zone. Only few tons of our chemicals react with hydrocarbons and most of residuals of the reactions are being washed out in few days. The remaining amounts are negligible and don’t influence specification of the oil during production after our treatment.

Q: How do we know that it is going to increase production in later time?
A: We have proven it with laboratory tests and experience.

Q: What are the mechanical effects on the well?
A: The chain of chemical reactions, taking place during the treatment, creates pulses of heat and pressure within the channels and fractions of the formation. These factors, along with chemical influence on the rock, lead to channels widening and creating additional microfractures.
At the first stage, the reactions, taking place within the wellbore, are relatively slow and they release a small part of the energy produced during the treatment. That is why temperature and pressure increasing inside the well is not significant.

Q: What is the «ideal» pressure in the well?
A: There is no «ideal» pressure in the well. We fit chemical composition of our mixtures for a wide range of physical conditions inside the well and formation. The first stage of the reactions takes place within the wellbore under hydrostatic pressure and we worked with a well depth varying from 250m to 6000m. Regarding the formation conditions, temperature over 500C and pressure over 30MPa are preferable.

Q: Middle East wells have high pressure. Is our method influencing this? Do we have an increase in pressure when using TBC method?
A: TBC method doesn’t influence the formation pressure. Main effect obtained is increasing permeability of bottom hole zone, opening closed porosity and decreasing oil wettability of the rock.

Q: Do we have any open-hole application?
A: Yes, but frankly speaking not too many. Since last time, we have improved our TBC method to take into consideration some technical complications which we have met at open holes.

Q: Chemicals used are viscous or light?
A: Both mixtures we use for the main treatment are viscous and heavy to prevent their diffusion in water.

Q: If there is a well with good, medium & bad permeability at the same time, can TBC method be used?
A: Yes. Surely, every case is special and we need to solve some technical problems to concentrate influence of the treatment on the most problematic parts of the formation.

Q: Do these chemicals damage ICD (inflow control devise — equipment used in open-hole wells)?
A: Both mixtures are non-hazardous while being separated, but the active gases produced during the first stage of the reaction can damage any metallic equipment. Therefore we design a technological scheme of the treatment in such way to avoid contact of the active gases with ICD, string and other metallic equipment.

Q: What is the depth of penetration that the formation is?
A: The depth depends on a construction of every reservoir. In most cases the strongest influence is obtained 20-50 meters from the hole. The same time we had some cases when we observed increase of productivity at the neighboring wells placed few hundred meters (500 and 800 namely) from the well under treatment and chemical tests have found some microscopic residuals of our chemicals in the oil from the wells.

Q: Do we do any lab search on core samples?
A: During more than 20 years of research we studied influence of our technology on many various core samples and our scientists have developed some typical solutions. Quite often we use some typical solution. In less common cases we do lab search on core samples to adjust our technology.

Q: In previous applications what was the maximum reservoir pressure? Did we have any damage in the cement band of the well?
A: The maximum reservoir pressure in previous applications was 67MPa (9720 psi). We never had any damage in the cement band of the well.

Q: What is the volume of liquid that we use in each treatment?
A: It depends on well construction. Mainly we use just a few cubic meters.

Q: Have we ever observed asphaltene during our treatments?
A: Yes. We have quite often met asphaltines in oil and we proved, both in laboratory tests and practical applications, that TBC treatment destroys molecules of asphaltine well and removes colmatation.

Q: Does processing limestone and dolomite, and carbonate formation in the sintering and gypsum. How solutions behave in these rocks.
A: Both belong to a class of mineral carbonates, i.e. salt of carbonic acid. Limestone – CaCO3 (the same formula is chalk and marble, they only have a different structure of the crystal lattice).

The chemical composition of dolomite – CaMg (CO3) 2. All carbonates are decomposed by strong acids. In this case, hydrochloric acid and nitric (these acids are formed in the formation by chemical reactions of reactants in solution. №1, №2, №3). Reactions proceed with the release of carbon dioxide by type: СаСО3 + 2 НСl = СаСl2 + Н2О + СО2 or CaMg(CO3)2 + 4HNO3 = Ca(NO3)2 +Mg(NO3) 2 + 2 Н2О + 2 СО2.

Carbon dioxide dramatically reduces the viscosity of the oil. There is even a method of treatment of shallow wells: operating the exhaust gases of the diesel engine is directed into the well… or burnt oil and gas is directed into the well.

Maximum temperature of the chemical processes in the formation of hydrogen at our reaction mode process of filtration combustion does not exceed 450 – 500 C. This process is possible and we apply it , if the porosity of the formation above 600 milli Darcy ( mD) .Carbonate reservoirs rarely have the structure and we work in the so-called active mode of cracking and cleaning the pore space of the organic and inorganic impurities. The temperature in the bed does not exceed 250 – 300 °C “Decomposition (dissociation ) of calcium carbonate and its sintering oxides occur at temperatures above 800 – 850 °C, and magnesium carbonate at a temperature of 600 – 650 °C. However, the processes of recrystallization and sintering of magnesium oxide occur much more intense than the processes of sintering and recrystallization of calcium oxide .Already at 1200-13000 C formed tightly calcined magnesium oxide , which reacts with water only for very fine grinding.” No sintering and thermal expansions for our treatments can not be.

Q: What is the depth of penetration into the formation of this method?
A: In laboratory tests, an analysis of the results, indicating that a complete thermochemical treatment causes the sintering rocks along the entire length of the sample , which in appearance resembles a porous ceramic.

The permeability of the core after the treatment is increased from 20 – 100 38 – 140 times depending on the composition and structure of the breed.

First to demonstrate that by moving of filtration combustion front in the reservoir model can be created thermo- chemical action of hydrogen and going after him, the flow of oxygen and other gases FOM (fuel – oxidant mixtures).

Combustion front moves at a speed of 5.8 – 6.5 mm/min. In the presence of boron-containing additives or nitrile maximum temperature reaches 871 – 879 K, (597,85 – 605,85 °C) and the movement speed of the combustion front accelerates to 8.7 – 8.9 mm/min.

Q: How the technology works in rocks with 95% inclusion of carbonates? Examples of work done.
A: This technology works in any types of reservoir. In carbonate reservoirs the applying of this technology will lead to micro fracturing of the formation, to opening the closed pores (it means that permeability will increase). Also this tech cleans existing pores and ways between them. This tech solves the contamination of the pay zone. Due to all this factors the production of the well will be increased.

For example: Russia, Perma region 100% carbonates. 1998 Before treating The output was 4 tons of oil per day. After 12 tones. Egypt Baharia region. 70% carbonates. 2013 Before treating the well produced 400 barrels per day. After 670 bar/day.

Q: Description of the impact of chemistry on paraffin sediments.
A: Description of the impact of chemistry on asphalten resinous paraffin sediments, paraffin sediments. Asphaltenes are black or brown hard, brittle, infusible high molecular substances with density more than. At temperatures above 300 °C asphaltenes decompose to produce gases and coke. Our reaction launches in the casing at a temperature of 230 – 250 C. Evolved gas is drawn into the reservoir, heating it to a temperature of 450-500 C. Atomic hydrogen release s first. Reaching the reservoir It reacts with oil components, in particular asphalten resinous paraffin sediments. This chemical reaction, launches isomerization of the molecule. Hydrogen isomerize asphalten resinous paraffin sediments and it decomposes, forming active carbon and etc. there is a chain reaction of hydrogen formation. Hydrogen is a long-lasting source of energy in the reservoir. That is, the process of combustion begins in the formation.

Combustion occurs involving coke and asphalten resinous paraffin sediments in the formation.

The technology can be applied with any density of oil.