Exxon, Conoco May Join Gazprom's Yamal LNG Projects
Weatherford's "Aquatic" Spreads the Gospel of Aluminiumfor Drilling Deep On and Offshore
Russian Industrialists Union Urges Support of Small Oil Producers
№ 6 (June 2008)
Most frequently, in using fuel oil one may encounter such problems as:
High water content in fuel oil and problems with its combustion. In many cases, water content in fuel oil significantly exceeds the maximum permissible values (instead of 1.5 percent, the water content reaches 12-16 percent, and in some cases – 20-35 percent). This results in serious problems of ignition and combustion process.
The VECTOR Unit Forms Stable Water-Fuel Emulsions
Most frequently, in using fuel oil one may encounter such problems as:
High water content in fuel oil and problems with its combustion. In many cases, water content in fuel oil significantly exceeds the maximum permissible values (instead of 1.5 percent, the water content reaches 12-16 percent, and in some cases – 20-35 percent). This results in serious problems of ignition and combustion process.
Expenses on separation water from fuel oil. Traditionally water is removed by sedimentation. Separation of phases “water-fuel oil” in settling storage tanks takes rather long time and is inefficient due to similar density of fuel oil and water.
Environmental pollution by the fuel oil combustion products (nitrogen oxides, carbon black, benzpyrene) and waste water containing petroleum products.
Fuel oil “ageing”. During long-term storing, light ends evaporate from the fuel oil, which results in increase of its viscosity and flash temperature. As a rule, after two or three years of storage, combustion of such fuel oil becomes problematic, and it needs to be replaced with a newer fuel oil.
Deterioration of the equipment and insufficient technological level of boiler plants. In some cases, the technical status of the system of fuel oil treatment is such that it becomes impossible to heat the fuel oil to the temperature required for combustion (at least 90 С). In the result of this, the fuel nozzles do not provide the required fuel oil spraying. And this, in its turn, results in higher incomplete chemical and mechanical combustion of fuel (carbon black), and in the end, in excessive consumption of the fuel oil.
Low-temperature sulfuric acid corrosion of metal surfaces of smoke channels.
Novyie Tekhnologii Company has developed a state-of–the-art technical solution, which enables product cavitational treatment and instantaneous mixing, thermal treatment, dispersion, destruction of the aggregate state, activation of chemical bonds, etc. The VECTOR unit is designed to solve problems of energy conservation and environmental safety during operation of fuel power plants and is most widely used for watered fuel oil treatment.
VECTOR enables a controlled cavitational action on the liquid molecular composition, which makes it possible to put together various liquids and form stable emulsions. The system is designed to prepare water fuel emulsions (WFE) on the basis of standard and degraded fuel oil, used oils, diesel and stove fuel, and refinery waste.
The technologies used in VECTOR system are based on the patented method of heat-mass-energy exchange and the device for its realization (Patent No. 2268772). This invention made it possible to develop such a method of acoustic intensification of heat-mass-energy exchange, which, by means of special arrangement of interaction of vortex flow, will make it possible to improve efficiency of transformation of the chemical bonds of disperse-aggregate state of the product, and also realize acoustic activation of chemical bonds at the molecular level.
Method for production of water-fuel emulsion implies the use of two components necessary to obtain the final product – fuel oil and water. Since water is relatively inexpensive, its use ensures considerable saving both in the process of preparation of WFE and in the result of the final product use. Moreover, alongside with reduction of atmospheric emission from WFE, oil-containing sewage water is effectively neutralized, which is important for the environment.
Technological Advantages of the Technology Application:
Ease of the unit introduction into the existing system of fuel supply.
Absence of revolving parts, which ensures the maximum duration of the unit service life.
Simplicity of the monitoring and control.
Retarded Acid DRA-2: Breaker Reinforcer Improves Fracturing in West Siberia
DRA-2 is a new additive that was successfully introduced by Newco Well Service during the field hydraulic fracturing operations. Being added to water solutions under high temperatures, this liquid additive slowly disengages organic acid. Such disengagement is featured by numerous advantages that are essential for high рН fracturing systems such as Quantum gels. The most obvious advantage is slowly decreasing рН in the course of acid disengagement. Decrease in рН below 8 completely removes borate crosslinkers both from hydrated polymer chains and polymer chain fragments after decomposition by oxidizing breaker. This process results in decreased unbound polymer fragments and therefore minimizes a potential for sedimentation that reduces conductivity of proppant pack.
Application of DRA-2 in combination with an oxidizing breaker results in synergetic degradation of the fracturing gel. There is one more advantage of adding DRA-2: in the course of disengagement, organic acid can completely decompose the fracturing gel. A long time period and high temperatures assist organic acid to hydrolyze polymeric chains; this reaction is similar to oxidation; incidentally chains are disintegrated generating minor fragments.
A synergetic effect of adding two breakers consists in retarded chemical interactions. Since DRA-2 is liquid and conventional oxidizers are encapsulated solid substances, DRA-2 is mixed with the fluid penetrating the reservoir while the oxidizer is in a crack. As a result the breaker is in every location where the fracturing liquid moves. The final liquid fracturing agent with low рН is featured by a number of advantages. It is known that liquids with high рН significantly damage sand formations with high concentrations of swelling and migrating clay. Many clay minerals are featured by a strong tendency to hydration at high рН (over 7). Decreasing рН of the fracturing liquid by means of DRA-2 results in decreased damage to clay from water penetrating the formation. In addition to obvious advantages of using DRA-2 in liquid fracturing agents, this unique additive can be applied otherwise. Laboratory testing proved that DRA-2 can be applied in combination with enzymatic breakers to decompose liquid fracturing agents with high рН such as Quantum gels. A conventional cellulose enzy e useful in combination with foaming additives (chemicals foaming water at high рН and not foaming at low рН). Deactivation of foaming additives is defined by obvious advantages during fracturing with a foaming agent or cleaning foaming fluids. DRA-2 is a cost effective, non-evaporating, non-flammable, and inodorous additive. This product is successfully applied at some fields in Western Siberia. Analysis of its application (see Fig. 1) confirms its efficiency as a whole for a group of wells.
CPS Trains Personnel at Dangerously Explosive Facilities
Human factor is one of the main causes of accidents at dangerously explosive facilities of the chemical, petrochemical and oil-refining industries.
Computer-based process simulator (CPS) is the most efficient tool for training of the operating and technical personnel of the dangerously explosive facilities. In accordance with the Safety Regulations PB 09-540-03, all employees of the plants having technological units of the first and second categories of hazard must take a training course on the computer-based simulators which are built on the basis of dynamic models. In addition, there is demand for computer-based process simulators (CPS) at other plants as well. The reason of this is that in the modern situation, at high level of automation, operating personnel loses practical skills of control to a considerable extent. That is why often in emergency situations they appear to be not ready to fulfill their functions.
NIIK (the Research and Design Institute of Carbamide and Organic Synthesis Products) designed a CPS intended for training and retraining of the personnel working at the dangerously explosive facilities, or at technically complex facilities of significant unit capacity, where the cost of accident consequences is high.
The functional structure of CPS includes the following:
Knowledge base (electronic documentation);
Subsystem of operating personnel training for the following:
1) Production control under the normal process conditions;
2) Production control in case of the process malfunction including emergency situations (procedure simulator);
3) Control under conditions of startup/shutdown.
Evaluation subsystem (in the form of testing).
The CPS has the following modes: personnel training with the help of the instructor or self-training. The simulator uses all multimedia tools available at present: graphics, sound, animation. It is built based on principles of modularity and openness, which enables the customer to expand and adapt the knowledge base, develop new training procedures.
CPS gives the trainee an opportunity to study the following through the computer monitor: the process, its technical characteristics, its instrument base, equipment setup, process modes, character of media flow, and processes in the vessels. CPS gives an opportunity to work with various drawings in digital form, study assembly and disassembly of the most complex equipment, the process schedule, instruction for work places and other documents which are to be studied. CPS makes it possible for the personnel to get skills of the process control both under the normal operating conditions and in the modes with various problems up to emergency situations.
CPS is based on simulators of the process and automatic control system (ACS).
The process simulator is built on the basis of the static and dynamic models of the process channels. The models use mathematical description of the material and heat balances of the vessels and process stages, description of the control object channels – with application of differential equations.
Control algorithms, closest to the actual ACS used for the process, are implemented as ACS simulators at CPS.
One of the CPS features is use of the quality process simulators which enable the personnel being trained to control the structure of multi-component media flows in the vessels (pipelines), i.e. flow rate of the components of complex media. In addition, process simulators ensure automatic control of the most important, instrumentally not measured qualitative parameters of the process.
This helps the trainee to better study the process statics and dynamics, process response to various control actions and master the methods and skills of control of the complex chemical-engineering process.
CPS was realized in carbamide production (company Eurochim NAK AZOT, town of Novomoscovsk, Tula region).
Polysilicate Briquettes Improve Oil Recovery
Russian and foreign companies have been applying sodium silicates to improve reservoir recovery for many years. These materials are quite efficient, inexpensive and environmentally safe. There are some application disadvantages, such as the low content of the active substance, freezing at temperatures below 0 С and the hampered timing of gellation.
Scientific and Production Center NOMAK has developed a new polysilicate grade of Silinom VN-M characterized by the following features: they contain at least 40 percent of silicon dioxide (SiO2), a polymeric content of 80 percent, non-freezing to temperatures of -40 С, and they withstand up to 10 freezing cycles.
A basic difference between high-alkali silicate systems (liquid silica glass) and polysilicates is that the latter contain polymeric silica forms representing polymeric silica spherocolloids with a diameter of 4 nm, the content of which is equal to or over 60 percent of the total silica content.
A structural element of all silicate glass grades is the silicon-oxygen tetrahedron with silicone atom Si4+ with coordination number 4 in the center and atoms О2- and cations in the tetrahedron corners.
Due to a double hydrate layer on the surface of silica micellae, polysilicate particles in this new product are cross-linked into a gel state by means of hydrogen bonds. In a diluted state the gel easily peptizes forming a polysilicate solution.
Polysilicates are applied as reagents during workover and isolation of wells in the oil and gas production industry, for preparation of binding materials for refractory and acid-resisting concretes, for the production of thermal insulation materials, and as a basic substance for creating mineral sealing plies of binder soils. Polysilicates are delivered in polypropylene bags or in big bags.
The efficiency of polysilicates is four times higher than the efficiency of normal silicates, which makes it possible to apply the processing medium at lower concentrations.
The lower concentration ensures low viscosity; therefore these solutions can be applied in wells with low permeability (injectability).
Process solutions are prepared on wells by simple dilution with water while mixing. They are generally compatible with applicable water soluble polymers.
Adjusting the ratio of the polysilicate and gelling agent makes its possible to form systems with a gel time of 4 to 48 hours.
In addition, the processing medium parameters can be changed by means of differential and integral calculus subject to changing well injectability.
The MTM Technology to be Verified at Oilfield Facilities in Russia and Abroad
In 2007, a number of inspections were performed aimed at verification of efficiency of the magnetic tomography method (MTM) for pipelines which cannot have inner inspection.
In Russia this work was done to evaluate the prospects of the new diagnostic technologies for TNK-BP. Two magnetic methods were tested: the magnetic tomography method (MTM) with the use of SKIF MBS-04 equipment (contractor NTTs Transkor-K); the method of metal magnetic memory (contractor Nefteservice, using instruments of Energodiagnostika), and also long-wave ultrasonic method of directional waves (contractor Ecolink, using ultrasonic system Wavemaker G3).
Oilfield pipelines became objects of the survey (Orenburgneft, TNK-Nizhnevartovsk, TNK-Nyagan, Samotlorneftegas, Vanyoganneft).
The work included inspection and measurements along the pipeline route; data interpretation; opening of pits for additional defectoscopy (AD) and issue of the report. Based on the AD results in control pits, the independent expert company Lisan prepared a report “Analysis of Non-Destructive Inspection of Oilfield Pipelines at the Facilities of TNK-BP”.
The analysis of MTM information value showed the following:
One hundred percent additional defectoscopy by arbitrary methods was performed at the dismantled sections of the pipeline (Fig. 1). Reliability or confidence level of identification of defective areas by MTM technology (contractor NTTs Transkor-K) appeared to be 70 percent, and in some cases 90 percent. The following demerits of the technology were observed: impossibility to immediately identify anomalous areas, as certain time is required for interpretation. It takes 24 hours for computer processing and interpretation of the data. In addition, “insufficient precision of the defect location” is stated – areas of up to 5 meters. However, it should be mentioned again that by definition, anomalies revealed by the MTM method are defect-containing areas of total extent up to several meters, and not “separate defects.” Thus, this comment in respect of the MTM method is not correct.
Besides, it was noted that MTM did not detect “wormholes and other defects in absence of stress concentration or magnetic field variation.” This comment is true and is given in the specification as the method limitation, i.e. it does not ensure detection of defects which cause no concentration of mechanical stresses. The fraction of these defects varied from 10 to 30 percent at various facilities of TNK-BP.
The following advantages of MTM were listed:
The method was certified at the Regional Mining and Technical Inspectorate;
It is possible to detect not only defective areas, but also places of the pipeline contact with foreign objects (other pipes, various metal pipes).
Detection of geometry variation in case of stressed state (mechanical damage, sagging, jamming, bending by the radii smaller than acceptable values.
Having fulfilled the studies, we would like to stress that internal corrosion defects make a significant portion of the detected defects of the oilfield facilities. Exactly these defects are the main cause of accidents (loss of integrity) at pipelines transporting corrosive products.
Large-scale inspections for MTM data verification were done at the foreign facility in Latin America. Characteristics of the facility: gas pipeline passing over the Mendoza Norte fields from the Gascon ll field to the Luján de Cuyo refinery, which is not subject to in-line inspection; its length is 18.6 km; the diameter is 10 in., wall thickness according to the AD data varies from 3.5 to 5.2 mm. Beforehand, possibilities of ILI, ECDA (CIPS, DCVG) methods were evaluated, and their effectiveness was compared to MTM.
The following was done to determine the MTM reliability:
– Sections with ten anomalies were cut out: five red, two yellow and three green ones.
– Visual and measuring control and ultrasonic checks were performed.
– The results of AD were compared to the MTM statement which was handed over.
– Two parameters were used for comparison:
1) Accuracy of defect hazard determination;
2) Defect detection capability.
Conclusions of the Argentinean company Repsol YPF, which performed the inspection (below is provided an extract from the report):
“Comparison of the method capabilities enabled us to make a conclusion on the best suitability of the MTM method because of impassability of the inner space of the pipeline and non-applicability of other methods for internal corrosion detection. The MTM method is a reliable tool for detection of the totality of defects of special significance – such as external and internal ‘metal loss’ and through-blowholes. Reliability of the method is 75-80 percent.
In relation to defects of medium and low significance, the method is not highly reliable, as contradictory predictions are made. Its reliability here is 60-65%. Such geometry defects as dents and traces of mechanical action are detected correctly.
The final reliability of the method is approximately 68-70 percent.
The method determines correctly the degree of anomaly hazard, but inaccuracy of separate defect type prediction is noted.
The developers recommend application of this method at the facilities where it is impossible to use ILI (in-line inspection – pig), or electrometry method ECDA in the areas with sensors of internal corrosion defects.”
Optimization of Impeller Support Washers Improves Efficiency of the ESPU
REAM-RTI, NOVOMET-Perm and KONNAS (Special Design Bureau of Rodless Pumps) supported by the Foundation for Assistance to Small Innovative Enterprises (FASIE), recently conducted a range of scientific, design and material engineering research tests intended to improve the abrasion resistance of submersible centrifugal pump stages under the conditions of super-high content of solid mechanical particles in the medium to be pumped.
As a result, a new design of impeller support washers has been developed to reduce aggregate wear in the support washer-diffuser collar more than ten times compared to textolite support washers. This will also reduce frictional torque by 3-8 percent, which increases the pump stage performance by 3-5 percent without changing the geometry of flow sections.
This concept uses special, capable of dry friction, abrasion-resistant elastomer composites developed with the application of nanotechnologies by specialists at REAM-RTI, working jointly with scientists at the Moscow State Institute of Steel and Alloys (the State Educational Institution of Higher Vocational Education).
Newly designed elastomers are intended for application in Electric Submersible Pump Units (ESPU) to be operated in super-complicated conditions such as a high gas-oil ratio, in all hydrocarbon environments including those containing up to 25 percent of hydrogen sulphide, and at a temperature up to 210 С of a liquid medium.
New design elastomer support washers are highlighted by their radial elasticity. Therefore, they can be used to replace all existing textolite support washers or washers made of other materials without changing the impeller design. The elasticity of elastomer support washers in axial direction reduces hydraulic and mechanical losses during impeller rotation.
REAM-RTI has also developed a technology of mass producing support washers made of special abrasion-resistant elastomer materials for impellers of major ESPU manufactured in Russia and recommends using these in the most complicated operation conditions; to maximize overhaul periods of pump units in case of increasing abrasive-carrying environment, and to reduce power consumption for their driving.