Adição de resíduo cerâmico em pastas geopoliméricas para cimentação de poços de petróleo

The development of activities the of oil and gas sector have promoted the search for suitable materials for cementing oil wells. In the state of the Rio Grande do Norte, the integrity of the cement sheath tends to be impaired during steam injection, a procedure necessary to increase oil recovery in reservoirs with low-viscosity oil. The geopolymer is a material that can be used as alternative cement, since it has been used in the production of fire-resistant components, building structures, and for the control of toxic or radioactive residues. Geopolymers result from condensation polymer alkali aluminosilicates and silicates resulting three-dimensional polymeric structures. They are produced in a manner different from that of Portland cement, which is made an activating solution that is mixed with geopolymer precursor. Among the few works studied allowed us to conclude that the pastes prepared with metakaolin as precursor showed better performance of its properties. Several studies show the addition of waste clay as a means of reducing cost and improving end of the folder properties. On this basis, the goal is to study the influence of the addition of ceramic waste in geopolymer paste. To develop the study of rheology tests were carried out, filtered, thickening time, compressive strength, free water, specific gravity and permeability, according to the American Pretoleum Institute (API). The results for all formulations studied show that the folders have high mechanical strength to a light paste; low filtrate volume, absence of free water, very low permeability, slurry, consistent with a light paste, and thickening time low that can be corrected with the use of a retardant handle. For morphological characterization, microstructural, physical, chemical and thermal tests were carried out by XRD, MEV, DTA, TG, FTIR. In the trial of XRD, it was found that geopolymer is an amorphous material, with a peak of crystalline kaolinite. In tests of TG / DTA, revealed the presence of a significant event, which represents the mass loss related to water, and also observed the reduction of weight loss by increasing the concentration of ceramic waste. In the trial of MEV, we found a uniform matrix without the presence of other phases. In the trial of FT-IR, we observed the presence of the band related to water. From all results it was determined that the optimum concentration range of use is between 2.5 and 5% of waste ceramic

Influência da vermiculita expandida na formulação de pastas leves para evitar a migração de gás em cimentação de poços petrolíferos

The gas migration during the cementing of wells is one of the main problems of oil wells engineering. Its occurrence can cause severe problems since shortly to loss of control of the well after cementation. Recently, 20/04/2010 In an accident of major proportions in the Gulf of Mexico, among other factors, faulty cementing operation provided the gas migration, causing the accident, in which 11 people died and 17 were injured occurred. Besides the serious consequences that can be caused by gas migration, remediation of the problem, which is made by injecting cement in damaged areas, usually involves additional costs and is not always effective. Therefore, preventing gas migration to be preferred. Some methods are used to prevent the migration of the pressurized gas as the annular space, application of pressure pulses, reducing the height of the cement column compressible cement pastes of low permeability, pastes and to control free filtered water, and binders of thixotropic cement expandable and flexible. Thus, the cement pastes used to prevent gas migration must meet the maximum these methods. Thus, this study aimed to formulate a cement paste to prevent gas migration, using the expanded vermiculite, and evaluate the behavior of the folder trials necessary for use in oil wells. Free water content, rheological properties, compressive strength, loss of liquid phase sedimentation of solids, specific weight, thickening time and gas migration: The following tests were performed. The results show that meets the specifications paste formulated for use in oil wells and the use of expanded vermiculite contribute to the absorption of free water, thixotropy and low density. The absorption of free water is proven to result in zero percentage test free water content, thixotropy is observed with the high value of the initial gel strength (Gi) in testing rheological properties and low density is proven in test weight specific

Estudo paramétrico da recuperação de óleo no processo de drenagem gravitacional com injeção de CO2

The gas injection has become the most important IOR process in the United States. Furthermore, the year 2006 marks the first time the gas injection IOR production has surpassed that of steam injection. In Brazil, the installation of a petrochemical complex in the Northeast of Brazil (Bahia State) offers opportunities for the injection of gases in the fields located in the Recôncavo Basin. Field-scale gas injection applications have almost always been associated with design and operational difficulties. The mobility ratio, which controls the volumetric sweep, between the injected gas and displaced oil bank in gas processes, is typically unfavorable due to the relatively low viscosity of the injected gas. Furthermore, the difference between their densities results in severe gravity segregation of fluids in the reservoirs, consequently leading to poor control in the volumetric sweep. Nowadays, from the above applications of gas injection, the WAG process is most popular. However, in attempting to solve the mobility problems, the WAG process gives rise to other problems associated with increased water saturation in the reservoir including diminished gas injectivity and increased competition to the flow of oil. The low field performance of WAG floods with oil recoveries in the range of 5-10% is a clear indication of these problems. In order to find na effective alternative to WAG, the Gas Assisted Gravity Drainage (GAGD) was developed. This process is designed to take advantage of gravity force to allow vertical segregation between the injected CO2 and reservoir crude oil due to their density difference. This process consists of placing horizontal producers near the bottom of the pay zone and injecting gás through existing vertical wells in field. Homogeneous models were used in this work which can be extrapolated to commercial application for fields located in the Northeast of Brazil. The simulations were performed in a CMG simulator, the STARS 2007.11, where some parameters and their interactions were analyzed. The results have shown that the CO2 injection in GAGD process increased significantly the rate and the final recovery of oil

Influência da adição de gres porcelanato no comportamento mecânico e microestrutural em pastas de cimento portland para cimentação de poços de petróleo

Cementation operation consists in an extremely important work for the phases of perforation and completion of oil wells, causing a great impact on the well productivity. Several problems can occur with the cement during the primary cementation, as well as throughout the productive period. The corrective operations are frequent, but they are expensive and demands production time. Besides the direct cost, prejudices from the interruption of oil and gas production till the implementation of a corrective operation must be also taken into account. The purpose of this work is the development of an alternative cement paste constituted of Portland cement and porcelainized stoneware residue produced by ceramic industry in order to achieve characteristics as low permeability, high tenacity, and high mechanical resistance, capable of supporting various operations as production or oil wells recuperation. Four different concentration measures of hydrated paste were evaluated: a reference paste, and three additional ones with ceramic residue in concentrations of the order of 10%, 20% and 30% in relation to cement dough. High resistance and low permeability were found in high concentration of residues, as well as it was proved the pozolanic reactivity of the residue in relation to Portland cement, which was characterized through x-ray and thermogravimetry assays. It was evident the decrease of calcium hydroxide content, once it was substituted by formation of new hydrated products as it was added ceramic residue

Nova técnica para obtenção de fraturas com altíssima condutividade em poços de petróleo

Increase hydrocarbons production is the main goal of the oilwell industry worldwide. Hydraulic fracturing is often applied to achieve this goal due to a combination of attractive aspects including easiness and low operational costs associated with fast and highly economical response. Conventional fracturing usually involves high-flowing high-pressure pumping of a viscous fluid responsible for opening the fracture in the hydrocarbon producing rock. The thickness of the fracture should be enough to assure the penetration of the particles of a solid proppant into the rock. The proppant is driven into the target formation by a carrier fluid. After pumping, all fluids are filtered through the faces of the fracture and penetrate the rock. The proppant remains in the fracture holding it open and assuring high hydraulic conductivity. The present study proposes a different approach for hydraulic fracturing. Fractures with infinity conductivity are formed and used to further improve the production of highly permeable formations as well as to produce long fractures in naturally fractured formations. Naturally open fractures with infinite conductivity are usually encountered. They can be observed in rock outcrops and core plugs, or noticed by the total loss of circulation during drilling (even with low density fluids), image profiles, pumping tests (Mini-Frac and Mini Fall Off), and injection tests below fracturing pressure, whose flow is higher than expected for radial Darcian ones. Naturally occurring fractures are kept open by randomly shaped and placed supporting points, able to hold the faces of the fracture separate even under typical closing pressures. The approach presented herein generates infinite conductivity canal held open by artificially created parallel supporting areas positioned both horizontally and vertically. The size of these areas is designed to hold the permeable zones open supported by the impermeable areas. The England & Green equation was used to theoretically prove that the fracture can be held open by such artificially created set of horizontal parallel supporting areas. To assess the benefits of fractures characterized by infinite conductivity, an overall comparison with finite conductivity fractures was carried out using a series of parameters including fracture pressure loss and dimensionless conductivity as a function of flow production, FOI folds of increase, flow production and cumulative production as a function of time, and finally plots of net present value and productivity index

Desenvolvimento de sistemas de pastas leves para aplicação em cimentação de poços petrolíferos com baixo gradiente de fratura

All around the world, naturally occurring hydrocarbon deposits, consisting of oil and gas contained within rocks called reservoir rocks , generally sandstone or carbonate exists. These deposits are in varying conditions of pressure and depth from a few hundred to several thousand meters. In general, shallow reservoirs have greater tendency to fracture, since they have low fracture gradient, ie fractures are formed even with relatively low hydrostatic columns of fluid. These low fracture gradient areas are particularly common in onshore areas, like the Rio Grande do Norte basin. During a well drilling, one of the most favorable phases for the occurrence of fractures is during cementing, since the cement slurry used can have greater densities than the maximum allowed by the rock structure. Furthermore, in areas which are already naturally fractured, the use of regular cement slurries causes fluid loss into the formation, which may give rise to failures cementations and formation damages. Commercially, there are alternatives to the development of lightweight cement slurries, but these fail either because of their enormous cost, or because the cement properties were not good enough for most general applications, being restricted to each transaction for which the cement paste was made, or both reasons. In this work a statistical design was made to determine the influence of three variables, defined as the calcium chloride concentration, vermiculite concentration and nanosilica concentration in the various properties of the cement. The use of vermiculite, a low density ore present in large amounts in northeastern Brazil, as extensor for cementing slurries, enabled the production of stable cements, with high water/cement ratio, excellent rheological properties and low densities, which were set at 12.5 lb / gal, despite the fact that lower densities could be achieved. It is also seen that the calcium chloride is very useful as gelling and thickening agent, and their use in combination with nanosilica has a great effect on gel strength of the cement. Hydrothermal Stability studies showed that the pastes were stable in these conditions, and mechanical resistance tests showed values of the order of up to 10 MPa

Estudo do potencial da técnica de nanossísmica para o monitoramento de hidrofraturamento em reservatórios de hidrocarbonetos

Hydraulic fracturing is an operation in which pressurised fluid is injected in the geological formation surrounding the producing well to create new permeable paths for hydrocarbons. The injection of such fluids in the reservoir induces seismic events. The measurement of this reservoir stimulation can be made by location these induced microseismic events. However, microseismic monitoring is an expensive operation because the acquisition and data interpretation system using in this monitoring rely on high signal-to-noise ratios (SNR). In general, the sensors are deployed in a monitoring well near the treated well and can make a microseismic monitoring quite an expensive operation. In this dissertation we propose the application of a new method for recording and location of microseismic events called nanoseismic monitoring (Joswig, 2006). In this new method, a continuous recording is performed and the interpreter can separate events from noise using sonograms. This new method also allows the location of seismic sources even when P and S phases onsets are not clear like in situations of 0 dB SNR. The clear technical advantage of this new method is also economically advantageous since the sensors can potentially be installed on the surface rather than in observation well. In this dissertation field tests with controlled sources were made. In the first test small explosives using fire works at 28 m (slant distances) were detected yealding magnitudes between -2.4 ≤ ML ≤ -1.6.. In a second test, we monitored perforation shots in a producing oil field. In this second test, one perforation shot was located with slant distances of 861 m and magnitude 2.4 ML. Data from the tests allow us to say that the method has potential to be used in the oil industry to monitor hydrofracture

A regulação da exploração e produção de hidrocarbonetos não convencionais no Brasil

The global energy crisis triggered the possibility of unconventional hydrocarbons exploration and production, culminating in the US energy revolution as well as making other countries interested in the development of these natural resources. The justification for this research comes from Brazil's interest in the use of hydraulic fracturing techniques in unconventional resources since the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) organized the 12th acquisition process and published the Resolution no. 21 of April 10, 2014. The conflict between economic viability and the social and environmental damage from exploration and production of unconventional hydrocarbons in Brazil resulted in the search for a legal solution that would consider the economic, social and environmental interests. The main purpose here is to analyze the regulation of unconventional oil exploration and production in Brazil in order to show lack of regulatory instruments so far. The specific objectives are to investigate how the lack of effective regulation may ultimately prevent the development itself, analyze the importance of systematization of a new regulatory tool for ensuring legal security and energy, identify the key negative environmental and social impacts, and suggest possibilities approaches within the new regulatory framework. The research methodology stands out the hypothetico-deductive model as approach, and the comparative model as procedural method. Moreover, the research techniques used here are performance of a theoretical and descriptive questioning over literature search, analysis of Brazilian standardization and case laws, and a brief comparative study, in order to provide suggested approaches for a new regulatory framework.

A regulação da exploração e produção de hidrocarbonetos não convencionais no Brasil

The global energy crisis triggered the possibility of unconventional hydrocarbons exploration and production, culminating in the US energy revolution as well as making other countries interested in the development of these natural resources. The justification for this research comes from Brazil's interest in the use of hydraulic fracturing techniques in unconventional resources since the Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) organized the 12th acquisition process and published the Resolution no. 21 of April 10, 2014. The conflict between economic viability and the social and environmental damage from exploration and production of unconventional hydrocarbons in Brazil resulted in the search for a legal solution that would consider the economic, social and environmental interests. The main purpose here is to analyze the regulation of unconventional oil exploration and production in Brazil in order to show lack of regulatory instruments so far. The specific objectives are to investigate how the lack of effective regulation may ultimately prevent the development itself, analyze the importance of systematization of a new regulatory tool for ensuring legal security and energy, identify the key negative environmental and social impacts, and suggest possibilities approaches within the new regulatory framework. The research methodology stands out the hypothetico-deductive model as approach, and the comparative model as procedural method. Moreover, the research techniques used here are performance of a theoretical and descriptive questioning over literature search, analysis of Brazilian standardization and case laws, and a brief comparative study, in order to provide suggested approaches for a new regulatory framework.

Adição de resíduo cerâmico em pastas geopoliméricas para cimentação de poços de petróleo

The development of activities the of oil and gas sector have promoted the search for suitable materials for cementing oil wells. In the state of the Rio Grande do Norte, the integrity of the cement sheath tends to be impaired during steam injection, a procedure necessary to increase oil recovery in reservoirs with low-viscosity oil. The geopolymer is a material that can be used as alternative cement, since it has been used in the production of fire-resistant components, building structures, and for the control of toxic or radioactive residues. Geopolymers result from condensation polymer alkali aluminosilicates and silicates resulting three-dimensional polymeric structures. They are produced in a manner different from that of Portland cement, which is made an activating solution that is mixed with geopolymer precursor. Among the few works studied allowed us to conclude that the pastes prepared with metakaolin as precursor showed better performance of its properties. Several studies show the addition of waste clay as a means of reducing cost and improving end of the folder properties. On this basis, the goal is to study the influence of the addition of ceramic waste in geopolymer paste. To develop the study of rheology tests were carried out, filtered, thickening time, compressive strength, free water, specific gravity and permeability, according to the American Pretoleum Institute (API). The results for all formulations studied show that the folders have high mechanical strength to a light paste; low filtrate volume, absence of free water, very low permeability, slurry, consistent with a light paste, and thickening time low that can be corrected with the use of a retardant handle. For morphological characterization, microstructural, physical, chemical and thermal tests were carried out by XRD, MEV, DTA, TG, FTIR. In the trial of XRD, it was found that geopolymer is an amorphous material, with a peak of crystalline kaolinite. In tests of TG / DTA, revealed the presence of a significant event, which represents the mass loss related to water, and also observed the reduction of weight loss by increasing the concentration of ceramic waste. In the trial of MEV, we found a uniform matrix without the presence of other phases. In the trial of FT-IR, we observed the presence of the band related to water. From all results it was determined that the optimum concentration range of use is between 2.5 and 5% of waste ceramic

Influência da vermiculita expandida na formulação de pastas leves para evitar a migração de gás em cimentação de poços petrolíferos

The gas migration during the cementing of wells is one of the main problems of oil wells engineering. Its occurrence can cause severe problems since shortly to loss of control of the well after cementation. Recently, 20/04/2010 In an accident of major proportions in the Gulf of Mexico, among other factors, faulty cementing operation provided the gas migration, causing the accident, in which 11 people died and 17 were injured occurred. Besides the serious consequences that can be caused by gas migration, remediation of the problem, which is made by injecting cement in damaged areas, usually involves additional costs and is not always effective. Therefore, preventing gas migration to be preferred. Some methods are used to prevent the migration of the pressurized gas as the annular space, application of pressure pulses, reducing the height of the cement column compressible cement pastes of low permeability, pastes and to control free filtered water, and binders of thixotropic cement expandable and flexible. Thus, the cement pastes used to prevent gas migration must meet the maximum these methods. Thus, this study aimed to formulate a cement paste to prevent gas migration, using the expanded vermiculite, and evaluate the behavior of the folder trials necessary for use in oil wells. Free water content, rheological properties, compressive strength, loss of liquid phase sedimentation of solids, specific weight, thickening time and gas migration: The following tests were performed. The results show that meets the specifications paste formulated for use in oil wells and the use of expanded vermiculite contribute to the absorption of free water, thixotropy and low density. The absorption of free water is proven to result in zero percentage test free water content, thixotropy is observed with the high value of the initial gel strength (Gi) in testing rheological properties and low density is proven in test weight specific

Estudo paramétrico da recuperação de óleo no processo de drenagem gravitacional com injeção de CO2

The gas injection has become the most important IOR process in the United States. Furthermore, the year 2006 marks the first time the gas injection IOR production has surpassed that of steam injection. In Brazil, the installation of a petrochemical complex in the Northeast of Brazil (Bahia State) offers opportunities for the injection of gases in the fields located in the Recôncavo Basin. Field-scale gas injection applications have almost always been associated with design and operational difficulties. The mobility ratio, which controls the volumetric sweep, between the injected gas and displaced oil bank in gas processes, is typically unfavorable due to the relatively low viscosity of the injected gas. Furthermore, the difference between their densities results in severe gravity segregation of fluids in the reservoirs, consequently leading to poor control in the volumetric sweep. Nowadays, from the above applications of gas injection, the WAG process is most popular. However, in attempting to solve the mobility problems, the WAG process gives rise to other problems associated with increased water saturation in the reservoir including diminished gas injectivity and increased competition to the flow of oil. The low field performance of WAG floods with oil recoveries in the range of 5-10% is a clear indication of these problems. In order to find na effective alternative to WAG, the Gas Assisted Gravity Drainage (GAGD) was developed. This process is designed to take advantage of gravity force to allow vertical segregation between the injected CO2 and reservoir crude oil due to their density difference. This process consists of placing horizontal producers near the bottom of the pay zone and injecting gás through existing vertical wells in field. Homogeneous models were used in this work which can be extrapolated to commercial application for fields located in the Northeast of Brazil. The simulations were performed in a CMG simulator, the STARS 2007.11, where some parameters and their interactions were analyzed. The results have shown that the CO2 injection in GAGD process increased significantly the rate and the final recovery of oil

Influência da adição de gres porcelanato no comportamento mecânico e microestrutural em pastas de cimento portland para cimentação de poços de petróleo

Cementation operation consists in an extremely important work for the phases of perforation and completion of oil wells, causing a great impact on the well productivity. Several problems can occur with the cement during the primary cementation, as well as throughout the productive period. The corrective operations are frequent, but they are expensive and demands production time. Besides the direct cost, prejudices from the interruption of oil and gas production till the implementation of a corrective operation must be also taken into account. The purpose of this work is the development of an alternative cement paste constituted of Portland cement and porcelainized stoneware residue produced by ceramic industry in order to achieve characteristics as low permeability, high tenacity, and high mechanical resistance, capable of supporting various operations as production or oil wells recuperation. Four different concentration measures of hydrated paste were evaluated: a reference paste, and three additional ones with ceramic residue in concentrations of the order of 10%, 20% and 30% in relation to cement dough. High resistance and low permeability were found in high concentration of residues, as well as it was proved the pozolanic reactivity of the residue in relation to Portland cement, which was characterized through x-ray and thermogravimetry assays. It was evident the decrease of calcium hydroxide content, once it was substituted by formation of new hydrated products as it was added ceramic residue

Nova técnica para obtenção de fraturas com altíssima condutividade em poços de petróleo

Increase hydrocarbons production is the main goal of the oilwell industry worldwide. Hydraulic fracturing is often applied to achieve this goal due to a combination of attractive aspects including easiness and low operational costs associated with fast and highly economical response. Conventional fracturing usually involves high-flowing high-pressure pumping of a viscous fluid responsible for opening the fracture in the hydrocarbon producing rock. The thickness of the fracture should be enough to assure the penetration of the particles of a solid proppant into the rock. The proppant is driven into the target formation by a carrier fluid. After pumping, all fluids are filtered through the faces of the fracture and penetrate the rock. The proppant remains in the fracture holding it open and assuring high hydraulic conductivity. The present study proposes a different approach for hydraulic fracturing. Fractures with infinity conductivity are formed and used to further improve the production of highly permeable formations as well as to produce long fractures in naturally fractured formations. Naturally open fractures with infinite conductivity are usually encountered. They can be observed in rock outcrops and core plugs, or noticed by the total loss of circulation during drilling (even with low density fluids), image profiles, pumping tests (Mini-Frac and Mini Fall Off), and injection tests below fracturing pressure, whose flow is higher than expected for radial Darcian ones. Naturally occurring fractures are kept open by randomly shaped and placed supporting points, able to hold the faces of the fracture separate even under typical closing pressures. The approach presented herein generates infinite conductivity canal held open by artificially created parallel supporting areas positioned both horizontally and vertically. The size of these areas is designed to hold the permeable zones open supported by the impermeable areas. The England & Green equation was used to theoretically prove that the fracture can be held open by such artificially created set of horizontal parallel supporting areas. To assess the benefits of fractures characterized by infinite conductivity, an overall comparison with finite conductivity fractures was carried out using a series of parameters including fracture pressure loss and dimensionless conductivity as a function of flow production, FOI folds of increase, flow production and cumulative production as a function of time, and finally plots of net present value and productivity index

Demanda química de oxigênio, clorofila a e comunidade fitoplanctônica como indicadores da qualidade da água no Canal do Pataxó/RN

The current study examined spatial-temporal modifications and water quality through chemical and biotic indicators during both dry (January, February and November 2006) and wet seasons (March to June 2006). This study was carried out in Armando Ribeiro Gonçalves Reservoir, RN, Canal do Pataxó and after the water station treatment (WST). The physical-chemical parameters were measured in situ and inorganic nutrients, chlorophyll a and Free Oxygen Demand (FOD) were analyzed in laboratory conditions. Quali quantitative analyses of phytoplankton were carried out utilizing Sedgwick-Rafter camera. Results indicate that DQO concentrations were low. FOD concentrations in the reservoir were comparatively higher in the dry season (5.21 mgL-1; 5.64 mgL-1 e 6.05 mgL-1) in relation to the wet season (4.52 mgL-1; 4.12 mgL-1 e 4.92 mgL-1), in surface, intermediate and bottom waters, respectively. FOD values were inferior to 1.0mgL-1in both Canal do Pataxó and after WST, which is considered adequate for public use reservoirs. Although FOD concentrations were low, Armando Ribeiro Gonçalves Reservoir, Canal do Pataxó and WST were classified as euthophizied, mesotrophic ad oligotrophic, respectively, considering the Index of Trophic State Criteria. Chlorophyll a concentrations in the study reservoir were higher in the surface (199.2 µgL-1) during the wet season, whereas in Canal do Pataxó concentrations decreased from 1.56 µgL-1 to 0.028 µgL-1, and after WST values were low (0.059 µgL-1). Dominance of cianobacterias, such as Planktotrhix agardhii (dry season) and Microcystis sp (wet season) was registered in all three areas. In the reservoir and Canal do Pataxó, density of cianobacterias, such as P. agardhii and Microcistys sp., was superior to the values allowed by the Health ministry (HM). However, after WST, density values of cianobacteria were inferior to values established by the HM