The constitutive equations for rocks are described. Linearity is assumed in the stress-strain rel... more The constitutive equations for rocks are described. Linearity is assumed in the stress-strain relationship. Such problems as reservoir compaction, overburden behavior, subsidence, and temperature effects are discussed. Some further areas of research concerning rock mass behavior prediction, laboratory data, interdependence with the fluid flow simulation, and field verification are also described. (MOW)
The overall objective of the research program is to develop the ability to predict the behavior o... more The overall objective of the research program is to develop the ability to predict the behavior of a geopressured reservoir during fluid withdrawal and reintroduction, as a means of determining stability of the overburden and surface during operation. While a research program in this area will be particularly related to the behavior of the reservoirs of the Texas Gulf Coast, many of the techniques and abilities developed will be applicable to other regions, given the necessary rock properties.
With the ever-increasing trend of oil production from lower pressure wells, application of artifi... more With the ever-increasing trend of oil production from lower pressure wells, application of artificial lift techniques is becoming inevitable. Beam pumps and electrical submersible pumps are two of the most common artificial lift methods for low and high oil production rates. But these techniques are susceptible to high gas-oil ratios, particularly at lower wellbore pressures causing gas break-out and possible gas lock. Various types of downhole separators have been recently designed upstream of the pump to resolve this issue and improve the pump efficiency. The objective of this study is to construct a state-of-art experimental facility and simulate the flow in an oil well with varying gas-oil ratios. The facility is then used to evaluate the performance of a centrifugal downhole separator. The experimental multiphase flow setup is designed, fabricated, and constructed in an efficient and automated way to simulate a typical horizontal wellbore. The well trajectory includes a 31-ft h...
Proceedings of SPE Rocky Mountain Regional Meeting, 1984
ABSTRACT Potential hazards of wireline exposures to hostile CO2 and H2S environments often discou... more ABSTRACT Potential hazards of wireline exposures to hostile CO2 and H2S environments often discourage running bottom hole pressure (BHP) surveys. While surface pressure build-ups may be utilized for dry-gas wells, detailed analyses may be of limited value where there is also liquid production. However, concurrent fluid level determinations can be used to enhance the value of surface build-ups. Other practical applications of fluid level determinations include a means of monitoring liquid loading or depths of fluid displacement, such as encountered during some stimulation or corrosion inhibition treatments. Detailed testing, of a recently developed high-pressure acoustical well sounder, verifies that fluid levels can now be determined even under the most adverse well conditions.
A procedure is described that allows an operator to identify those beam pumped wells which are op... more A procedure is described that allows an operator to identify those beam pumped wells which are operating at reduced efficiency. The logical sequence of steps to be followed in acquiring performance data such as power, dynamometer, fluid level, etc. and the criteria to be used in determining the causes of inefficiency are presented with the objective of reducing the time and effort required to perform the analysis.
The need for oilfield operators to verify that wells are being produced at their optimum capacity... more The need for oilfield operators to verify that wells are being produced at their optimum capacity and in a cost effective manner Is always present. The need to reduce operating costs, increase oil production and increase net income from wells requires an Integrated analysis of the pumping system Including the performance and interaction of all the elements: the reservoir, wellbore, the downhole pump, the gas separator and the prime mover. The analysis is to be made based on data obtained at the surface without entering the wellbore and must yield an accurate representation of conditions that exist on the surface, within the wellbore and within the reservoir. This paper presents a modern and logical approach to the solution of this problem through the use of Windows based applications and Sigma-Delta state of the art data acquisition hardware.
Throughout the world the most commonly used method to artificially produce wells is by sucker rod... more Throughout the world the most commonly used method to artificially produce wells is by sucker rod lift. Low producing efficiency caused by incomplete pump fillage is the most common operational problem experienced by sucker rod lifted wells. Incomplete pump fillage is the result of having a pump capacity that exceeds the production rate of the well or having poor gas separation at the pump intake with a portion of the pump displacement being lost to gas interference. More efficient operations and lower cost will result, if these wells are operated with the pump filled with liquid by eliminating any gas interference in the pump and controlling pump run time so the pump displacement will match the inflow of liquid from the reservoir into the wellbore. The operator must monitor well to insure that the pump has no mechanical problems and efficient operations are maintained as all the available liquid is produced from the wellbore.
Berea and Bandera sandstone samples were impacted with both 3/4-in. and 1/2-in. long wedges, each... more Berea and Bandera sandstone samples were impacted with both 3/4-in. and 1/2-in. long wedges, each having a 60° included angle and a 0.05-in. flat, at various confining pressures, with borehole and pore pressures held fixed at atmospheric pressure. Samples were saturated with air, water, glycerine-water, soltrol, mineral oil and soltrol, mineral oil mixtures to obtain a wide range of pore fluid viscosity. Penetration depth was held constant at 0.1 in. Dry and soltrol-mineral oil-saturated Berea samples were impacted at depths of penetration from 0.01 to 0.04 in. under 1,000 psi confining pressure to study crater initiation. Results indicate that viscosity of the pore fluid is influential primarily during the early stages of crater formation. Differences in bit force, crater volume and blow energy for tests parallel and perpendicular to bedding were significant, but decreased as the stress state was elevated. Crater volume, blow energy and bit force were nonlinearly related with depth...
Acoustic liquid level tests are performed successfully in many different applications throughout ... more Acoustic liquid level tests are performed successfully in many different applications throughout the world. Advanced techniques for acoustic liquid level analysis are required for wells where unusual conditions exist such as very shallow liquid levels, annular partial obstructions, flush pipe, short tubing joints, etc. Some wells have liners, upper perforations, paraffin, odd length of tubing joints, poor surface connections and other conditions which result in an acoustic trace that may be very difficult to interpret. Normally, the computer software locates the liquid level and automatically processes collar reflections to accurately count almost all of the collars from the initial blast to the liquid level. This automatic analysis will determine the liquid level depth for 95% of the wells. However, some wells have conditions or anomalies that these procedures will not function as desired. This paper describes special advanced techniques that can be used to determine the liquid lev...
Oilfield operators continually need to verify that their wells are being produced at the optimum ... more Oilfield operators continually need to verify that their wells are being produced at the optimum capacity and in a cost effective manner. An integrated analysis of the pumping system is required to reduce operating costs, increase oil production and increase net income. The integrated analysis of the pumping system must include the performance and interaction of all the elements: the prime mover, surface equipment, well bore equipment, down hole pump, down hole gas separator and the reservoir. This integrated analysis methodology is called Total Well Management, TWM. The TWM analysis is made based on data obtained at the surface without entering the well bore and yields an accurate representation of the conditions existing on the surface, within the well bore and within the reservoir. A field case study of a sucker rod lifted well illustrates the procedure and benefits of the Total Well Management methodology.
A decentralized downhole gas separator has been designed and successfully field tested in numerou... more A decentralized downhole gas separator has been designed and successfully field tested in numerous beam-pumped wells which were subject to severe gas interference. This paper presents a detailed description of the new gas separator which improves the performance of beam pumped wells. The decentralized gas separator places the gas separator housing against the casing wall by use of a bow spring on one side of the separator. The gas separator has ports on the opposite side of the spring, which are positioned against the wall where the liquid concentration is greater than in the larger section of the annulus where the flow is predominantly gas. A significant number of wells suffer from gas interference. If the pump is positioned above the formation, liquid separation from gas is very difficult especially at high annular gas flow rates. Significant increases in oil production are possible with use of the decentralized gas separator when gas interference hinders efficient pump operation....
The objective of this work is to present the concept of the Electrical Submersible Jet Pump (ESJP... more The objective of this work is to present the concept of the Electrical Submersible Jet Pump (ESJP). It is a new artificial-lift method for application in the petroleum production industry This proposed artificial-lift method uses an electrical submersible multistage centrifugal pump in combination with a jet pump installed in the well bore along the tubing string. Such a method is proposed to allow production of high gas- liquid-ratio petroleum wells using the existing electrical submersible pump technology. While applicable to any petroleum well, the driving force and main motivation for the development of this new technology is deep offshore petroleum production. In this work, also presented is a numerical model developed to simulate the operation of the system. In such a model, the system is analyzed as three coupled subsystems: the electrical submersible pump (ESP), the low gas-liquid-ratio (GLR) multiphase flow in the tubing string, and finally the flow inside the jet pump (JP)...
The constitutive equations for rocks are described. Linearity is assumed in the stress-strain rel... more The constitutive equations for rocks are described. Linearity is assumed in the stress-strain relationship. Such problems as reservoir compaction, overburden behavior, subsidence, and temperature effects are discussed. Some further areas of research concerning rock mass behavior prediction, laboratory data, interdependence with the fluid flow simulation, and field verification are also described. (MOW)
The overall objective of the research program is to develop the ability to predict the behavior o... more The overall objective of the research program is to develop the ability to predict the behavior of a geopressured reservoir during fluid withdrawal and reintroduction, as a means of determining stability of the overburden and surface during operation. While a research program in this area will be particularly related to the behavior of the reservoirs of the Texas Gulf Coast, many of the techniques and abilities developed will be applicable to other regions, given the necessary rock properties.
With the ever-increasing trend of oil production from lower pressure wells, application of artifi... more With the ever-increasing trend of oil production from lower pressure wells, application of artificial lift techniques is becoming inevitable. Beam pumps and electrical submersible pumps are two of the most common artificial lift methods for low and high oil production rates. But these techniques are susceptible to high gas-oil ratios, particularly at lower wellbore pressures causing gas break-out and possible gas lock. Various types of downhole separators have been recently designed upstream of the pump to resolve this issue and improve the pump efficiency. The objective of this study is to construct a state-of-art experimental facility and simulate the flow in an oil well with varying gas-oil ratios. The facility is then used to evaluate the performance of a centrifugal downhole separator. The experimental multiphase flow setup is designed, fabricated, and constructed in an efficient and automated way to simulate a typical horizontal wellbore. The well trajectory includes a 31-ft h...
Proceedings of SPE Rocky Mountain Regional Meeting, 1984
ABSTRACT Potential hazards of wireline exposures to hostile CO2 and H2S environments often discou... more ABSTRACT Potential hazards of wireline exposures to hostile CO2 and H2S environments often discourage running bottom hole pressure (BHP) surveys. While surface pressure build-ups may be utilized for dry-gas wells, detailed analyses may be of limited value where there is also liquid production. However, concurrent fluid level determinations can be used to enhance the value of surface build-ups. Other practical applications of fluid level determinations include a means of monitoring liquid loading or depths of fluid displacement, such as encountered during some stimulation or corrosion inhibition treatments. Detailed testing, of a recently developed high-pressure acoustical well sounder, verifies that fluid levels can now be determined even under the most adverse well conditions.
A procedure is described that allows an operator to identify those beam pumped wells which are op... more A procedure is described that allows an operator to identify those beam pumped wells which are operating at reduced efficiency. The logical sequence of steps to be followed in acquiring performance data such as power, dynamometer, fluid level, etc. and the criteria to be used in determining the causes of inefficiency are presented with the objective of reducing the time and effort required to perform the analysis.
The need for oilfield operators to verify that wells are being produced at their optimum capacity... more The need for oilfield operators to verify that wells are being produced at their optimum capacity and in a cost effective manner Is always present. The need to reduce operating costs, increase oil production and increase net income from wells requires an Integrated analysis of the pumping system Including the performance and interaction of all the elements: the reservoir, wellbore, the downhole pump, the gas separator and the prime mover. The analysis is to be made based on data obtained at the surface without entering the wellbore and must yield an accurate representation of conditions that exist on the surface, within the wellbore and within the reservoir. This paper presents a modern and logical approach to the solution of this problem through the use of Windows based applications and Sigma-Delta state of the art data acquisition hardware.
Throughout the world the most commonly used method to artificially produce wells is by sucker rod... more Throughout the world the most commonly used method to artificially produce wells is by sucker rod lift. Low producing efficiency caused by incomplete pump fillage is the most common operational problem experienced by sucker rod lifted wells. Incomplete pump fillage is the result of having a pump capacity that exceeds the production rate of the well or having poor gas separation at the pump intake with a portion of the pump displacement being lost to gas interference. More efficient operations and lower cost will result, if these wells are operated with the pump filled with liquid by eliminating any gas interference in the pump and controlling pump run time so the pump displacement will match the inflow of liquid from the reservoir into the wellbore. The operator must monitor well to insure that the pump has no mechanical problems and efficient operations are maintained as all the available liquid is produced from the wellbore.
Berea and Bandera sandstone samples were impacted with both 3/4-in. and 1/2-in. long wedges, each... more Berea and Bandera sandstone samples were impacted with both 3/4-in. and 1/2-in. long wedges, each having a 60° included angle and a 0.05-in. flat, at various confining pressures, with borehole and pore pressures held fixed at atmospheric pressure. Samples were saturated with air, water, glycerine-water, soltrol, mineral oil and soltrol, mineral oil mixtures to obtain a wide range of pore fluid viscosity. Penetration depth was held constant at 0.1 in. Dry and soltrol-mineral oil-saturated Berea samples were impacted at depths of penetration from 0.01 to 0.04 in. under 1,000 psi confining pressure to study crater initiation. Results indicate that viscosity of the pore fluid is influential primarily during the early stages of crater formation. Differences in bit force, crater volume and blow energy for tests parallel and perpendicular to bedding were significant, but decreased as the stress state was elevated. Crater volume, blow energy and bit force were nonlinearly related with depth...
Acoustic liquid level tests are performed successfully in many different applications throughout ... more Acoustic liquid level tests are performed successfully in many different applications throughout the world. Advanced techniques for acoustic liquid level analysis are required for wells where unusual conditions exist such as very shallow liquid levels, annular partial obstructions, flush pipe, short tubing joints, etc. Some wells have liners, upper perforations, paraffin, odd length of tubing joints, poor surface connections and other conditions which result in an acoustic trace that may be very difficult to interpret. Normally, the computer software locates the liquid level and automatically processes collar reflections to accurately count almost all of the collars from the initial blast to the liquid level. This automatic analysis will determine the liquid level depth for 95% of the wells. However, some wells have conditions or anomalies that these procedures will not function as desired. This paper describes special advanced techniques that can be used to determine the liquid lev...
Oilfield operators continually need to verify that their wells are being produced at the optimum ... more Oilfield operators continually need to verify that their wells are being produced at the optimum capacity and in a cost effective manner. An integrated analysis of the pumping system is required to reduce operating costs, increase oil production and increase net income. The integrated analysis of the pumping system must include the performance and interaction of all the elements: the prime mover, surface equipment, well bore equipment, down hole pump, down hole gas separator and the reservoir. This integrated analysis methodology is called Total Well Management, TWM. The TWM analysis is made based on data obtained at the surface without entering the well bore and yields an accurate representation of the conditions existing on the surface, within the well bore and within the reservoir. A field case study of a sucker rod lifted well illustrates the procedure and benefits of the Total Well Management methodology.
A decentralized downhole gas separator has been designed and successfully field tested in numerou... more A decentralized downhole gas separator has been designed and successfully field tested in numerous beam-pumped wells which were subject to severe gas interference. This paper presents a detailed description of the new gas separator which improves the performance of beam pumped wells. The decentralized gas separator places the gas separator housing against the casing wall by use of a bow spring on one side of the separator. The gas separator has ports on the opposite side of the spring, which are positioned against the wall where the liquid concentration is greater than in the larger section of the annulus where the flow is predominantly gas. A significant number of wells suffer from gas interference. If the pump is positioned above the formation, liquid separation from gas is very difficult especially at high annular gas flow rates. Significant increases in oil production are possible with use of the decentralized gas separator when gas interference hinders efficient pump operation....
The objective of this work is to present the concept of the Electrical Submersible Jet Pump (ESJP... more The objective of this work is to present the concept of the Electrical Submersible Jet Pump (ESJP). It is a new artificial-lift method for application in the petroleum production industry This proposed artificial-lift method uses an electrical submersible multistage centrifugal pump in combination with a jet pump installed in the well bore along the tubing string. Such a method is proposed to allow production of high gas- liquid-ratio petroleum wells using the existing electrical submersible pump technology. While applicable to any petroleum well, the driving force and main motivation for the development of this new technology is deep offshore petroleum production. In this work, also presented is a numerical model developed to simulate the operation of the system. In such a model, the system is analyzed as three coupled subsystems: the electrical submersible pump (ESP), the low gas-liquid-ratio (GLR) multiphase flow in the tubing string, and finally the flow inside the jet pump (JP)...
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Papers by Augusto L Podio