Xueyu Pang - Academia.edu (original) (raw)

Papers by Xueyu Pang

SPE Bergen One Day Seminar, 2016

Science and Engineering of Composite Materials, 2014

Science and Engineering of Composite Materials, 2015

SPE European Formation Damage Conference and Exhibition, 2015

Abu Dhabi International Petroleum Exhibition and Conference, 2014

Disposing spent mushroom substrate has been a major problem faced by farmers especially in areas ... more Disposing spent mushroom substrate has been a major problem faced by farmers especially in areas such as Pennsylvania where its output far exceeds existing demand. And the high soluble salts concentration of these wastes has restricted their immediate application in the agricultural arena. Widespread and year-round field inventories of spent mushroom substrate created a great environmental nuisance because of various pollutants contained in the waste. In this research, we are trying to come up with a solution to recycle this farm waste as a part of concrete materials. They may be added as a sand substitute into those concrete used in constructing sidewalks, ground support for signboards or posts, sound walls, and other non-structural facilities. It was found that these wastes should be treated with quicklime or cement before being mixed into concrete as a partial substitute for sand. In order to make the recycling process both economical and applicable, the minimal amount of quickli...

Civil and Environmental Engineering Dept. Thesis (M.C.E.)--Villanova University, 2007. Includes b... more Civil and Environmental Engineering Dept. Thesis (M.C.E.)--Villanova University, 2007. Includes bibliographical references (l. 71-74).

This dissertation mainly focuses on studying the fundamental hydration kinetics and mechanisms of... more This dissertation mainly focuses on studying the fundamental hydration kinetics and mechanisms of Portland cement as well as the effects of curing temperature and pressure on its various properties. An innovative test apparatus has been developed in this study to cure and test cement paste specimens under in-situ conditions, such as down-hole in oil wells with high temperature and high pressure. Two series of tests were performed using cement pastes prepared with four different classes of oilwell cement (namely Class A, C, G, and H cements). Specimens in groups of four were cured at temperatures ranging from ambient to 60 °C and pressures ranging from 0.69 to 51.7 MPa for a period of 48 or 72 hours. The density and w/c ratio of the specimens at the time of casting as well as at the end of the curing period were recorded. Total chemical shrinkage of the cement paste was measured continuously during the entire hydration period while tensile strength was obtained at the end of the curi...

Because varying the load distribution across a loading axle or in between two axles can change su... more Because varying the load distribution across a loading axle or in between two axles can change substantially the dynamic forces on both the front and rear wheels of a vehicle, a simple two-contact model is applied in this investigation to compute the effect of the vehicle load distribution on the dynamic forces exerted on pavement surfaces in terms of various physical parameters characterizing the vehicle-road interaction. The proposed model becomes an axle load model when placed perpendicular to a wheel path; and it can be a half of a vehicle model when placed along a wheel path. Dynamic responses of the models are computed in Excel worksheets in terms of the vehicle characteristics and the characteristics of road profiles. The intensities for both the rates of the dynamic forces and the dynamic forces are evaluated by considering the rotational effect induced by road profiles. It is demonstrated that the pitch & roll motion can change substantially the magnitudes of these dynamic ...

In this study the hydration kinetics of four different types of cements during early ages were in... more In this study the hydration kinetics of four different types of cements during early ages were investigated by both chemical shrinkage and isothermal calorimetry tests. Chemical shrinkage tests were performed at both different temperatures and pressures while isothermal calorimetry tests were conducted only at different temperatures. The hydration kinetics curves at different curing conditions were found to converge reasonably well if properly transformed with a set of scaling factors. Therefore, the experimental hydration kinetics curve at one curing condition can be used to predict that of another curing condition using a single scale factor. The scale factor is similar to the coefficient used to compute the equivalent age of a specified curing condition when applying the maturity method to estimate concrete strength. Its dependence on curing temperature and curing pressure can be modeled by the activation energy and the activation volume of the cement, respectively .

Construction and Building Materials, 2015

ABSTRACT The hydration kinetics of Class H oil well cement with and without chloride accelerators... more ABSTRACT The hydration kinetics of Class H oil well cement with and without chloride accelerators were evaluated via isothermal calorimetry. A series of tests were conducted with two different water-to-cement (w/c) ratios (0.38 and 0.91) at two different temperatures (15 °C and 25 °C). The test results indicate that the effect of different chlorides on the overall cement hydration rate is primarily determined by the molar concentration of the chloride in water and can be simulated by a generalized scale factor model. At concentrations up to 0.9 M Cl−, the overall hydration rate increases approximately linearly with the CaCl2 concentration and shows virtually no dependence on temperature and w/c ratio. In contrast, when NaCl or KCl is used at similar concentrations (up to 0.9 M Cl−), the hydration rate increases linearly with the logarithm of the chloride concentration and the correlation varies slightly with temperature and w/c ratio.

Cement and Concrete Research, 2014

ABSTRACT A series of NMR and isothermal calorimetry tests were conducted to depict a retarder exc... more ABSTRACT A series of NMR and isothermal calorimetry tests were conducted to depict a retarder exchange mechanism whereby a powerful organophosphonate retarder (nitrilotris(methylene) triphosphonate, or NTMP) is replaced by a much weaker phosphate retarder (sodium hexametaphosphate, or SHMP). The retardation of cement hydration by NTMP is believed to be primarily attributed to the dissolution of calcium from the cement and the subsequent precipitation of a layered calcium phosphonate that binds to the surface of the cement grains and strongly inhibits further hydration. The test results from this study show that the addition of SHMP helps to dissolve the precipitated calcium phosphonate and thus removes the strong retardation effect of NTMP. The proposed retarder exchange mechanism may be employed to develop cement systems with a controlled setting behavior.

SPE International Oilfield Nanotechnology Conference and Exhibition, 2012

ABSTRACT Nanotechnology encompasses a wide scope of disciplines and nanomaterials are now being u... more ABSTRACT Nanotechnology encompasses a wide scope of disciplines and nanomaterials are now being used as commercially viable solutions to technical challenges in industries ranging from electronics to bio-medicine. Recently, the application of nanomaterials to solve problems in oilwell cementing has begun to be investigated by several different research groups in the oil and gas industry. The following uses of nanomaterials have been presented by several independent laboratories as possibilities in the oilwell cementing industry: (1) nanosilica and nanoalumina as potential accelerators; (2) nanomaterials including carbon nanotubes (CNTs) with high aspect ratio to enhance mechanical properties; (3) nanomaterials to reduce permeability/porosity; and (4) nanomaterials to increase thermal and/or electrical conductivity. In this paper, a review of the aforementioned application concepts is presented with a focus on understanding the role of multiwall CNTs (MWNTs), nanosilica, and nanoalumina in oilwell cement hydration chemistry. The influence of the integration of MWNTs into oilwell cement on the physical properties of cement is discussed. Results from an isothermal microcalorimetric study are presented to help understand the difference between the mode of acceleration of a typical cement accelerator, like CaCl2, compared to nanosilica and/or nanoalumina.Introduction In recent years, the conceptual framework of nanotechnology has demonstrated utility across a wide variety of industries, from textiles and defense to aerospace and energy. While the materials in these industries can vary greatly, the fundamental concept that a superior and more functional organization of matter is achieved through an intelligent design from the "bottom up?? remains the same. This is no different in the cement industry, where self-sensing, self-healing, self-cleaning, and strength enhancement are concepts now frequently discussed in the research community. The inclusion of nanoscale particles into Portland cement paste, mortar, or concrete can impart functionality into cements yielding a variety of different emergent property enhancements. Generally, nanomaterial induced property enhancements have been observed and reported to include (1) early strength development, (2) increased long-term tensile-to-compressive-strength ratio, (3) viscosity enhancement, and (4) overall increases in the early-stage compressive strength. These modifications and enhancements are attributed to factors such as densification, particle packing, acceleration, high surface area, increased nucleation sites, and structural reinforcement. This paper focuses on the influence of nanoparticles, specifically on the fresh and the hardened properties of the mixture (Senff et al. 2010; Jalal et al. 2012; Khaloo et al. 2011; Leemann and Winnefeld 2007; Hosseini et al. 2010; Ozyildirim and Zegetosky 2010; Gaitero et al. 2010; Shih et al. 2006; Ltifi et al. 2011; Gaitero et al. 2008). In particular, how nanosilica and nanoalumina can act as potential accelerators is investigated. How CNTs with high aspect ratios can enhance the mechanical properties of cements is also discussed. Certain nanomaterials that serve to reduce the cement's permeability/porosity are described, and how some nanomaterials increase the thermal and/or electrical conductivity in cement is briefly addressed.

IADC/SPE Drilling Conference and Exhibition, 2014

IADC/SPE Drilling Conference and Exhibition, 2014

Construction and Building Materials, 2015

ABSTRACT Cement chemical shrinkage under pressure can be measured by an injection pump.•Chemical ... more ABSTRACT Cement chemical shrinkage under pressure can be measured by an injection pump.•Chemical shrinkage increases with increasing temperature during early stage.•Curing pressure up to 13 MPa has relatively little effect on chemical shrinkage.•Hydraulic fracture method may be used to obtain the in-situ strength of well cement.

Construction and Building Materials, 2015

ABSTRACT A variety of different types of oil well cement were tested with a newly developed test ... more ABSTRACT A variety of different types of oil well cement were tested with a newly developed test apparatus under different curing conditions to study the effects of curing temperature and pressure on their tensile test behavior. Specimens were cured at temperatures ranging from 24 to 60 °C and pressures ranging from 0.69 to 51.7 MPa. Tensile tests were performed at the age of 72 h. The capability of the test apparatus to record system deformation during pressurization and depressurization also allows study of cement–water interactions at different curing stages. Both splitting tensile tests and water pressure tensile tests were conducted after depressurization for assessing possible damage induced by the pressure change. A potential damage mechanism of set cement during depressurization is proposed in this study by analyzing the system deformation and tensile strength test data.

Cement and Concrete Research, 2013

ABSTRACT The heat evolution of Class G and Class H oil well cements cured under different tempera... more ABSTRACT The heat evolution of Class G and Class H oil well cements cured under different temperatures (25 °C to 60 °C) and pressures (2 MPa to 45 MPa) was examined by isothermal calorimetry. Curing pressure was found to have a similar effect on cement hydration kinetics as curing temperature. Under isothermal and isobaric conditions, the dependency of cement hydration kinetics on curing temperature and pressure can be modeled by a scale factor which is related to the activation energy and the activation volume of the cement. The estimated apparent activation energy of the different cements at 2 MPa varies from 38.7 kJ/mol to 41.4 kJ/mol for the temperature range of 25 °C to 40 °C, which decreases slightly with increasing curing temperature and pressure. The estimated apparent activation volume of the cements at 25 °C varies from − 23.1 cm3/mol to − 25.9 cm3/mol for the pressure range studied here, which also decreases slightly in magnitude with increasing curing temperature.

ACI Materials Journal, 2012

Cement and Concrete Composites, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

SPE Bergen One Day Seminar, 2016

Science and Engineering of Composite Materials, 2014

Science and Engineering of Composite Materials, 2015

SPE European Formation Damage Conference and Exhibition, 2015

Abu Dhabi International Petroleum Exhibition and Conference, 2014

Disposing spent mushroom substrate has been a major problem faced by farmers especially in areas ... more Disposing spent mushroom substrate has been a major problem faced by farmers especially in areas such as Pennsylvania where its output far exceeds existing demand. And the high soluble salts concentration of these wastes has restricted their immediate application in the agricultural arena. Widespread and year-round field inventories of spent mushroom substrate created a great environmental nuisance because of various pollutants contained in the waste. In this research, we are trying to come up with a solution to recycle this farm waste as a part of concrete materials. They may be added as a sand substitute into those concrete used in constructing sidewalks, ground support for signboards or posts, sound walls, and other non-structural facilities. It was found that these wastes should be treated with quicklime or cement before being mixed into concrete as a partial substitute for sand. In order to make the recycling process both economical and applicable, the minimal amount of quickli...

Civil and Environmental Engineering Dept. Thesis (M.C.E.)--Villanova University, 2007. Includes b... more Civil and Environmental Engineering Dept. Thesis (M.C.E.)--Villanova University, 2007. Includes bibliographical references (l. 71-74).

This dissertation mainly focuses on studying the fundamental hydration kinetics and mechanisms of... more This dissertation mainly focuses on studying the fundamental hydration kinetics and mechanisms of Portland cement as well as the effects of curing temperature and pressure on its various properties. An innovative test apparatus has been developed in this study to cure and test cement paste specimens under in-situ conditions, such as down-hole in oil wells with high temperature and high pressure. Two series of tests were performed using cement pastes prepared with four different classes of oilwell cement (namely Class A, C, G, and H cements). Specimens in groups of four were cured at temperatures ranging from ambient to 60 °C and pressures ranging from 0.69 to 51.7 MPa for a period of 48 or 72 hours. The density and w/c ratio of the specimens at the time of casting as well as at the end of the curing period were recorded. Total chemical shrinkage of the cement paste was measured continuously during the entire hydration period while tensile strength was obtained at the end of the curi...

Because varying the load distribution across a loading axle or in between two axles can change su... more Because varying the load distribution across a loading axle or in between two axles can change substantially the dynamic forces on both the front and rear wheels of a vehicle, a simple two-contact model is applied in this investigation to compute the effect of the vehicle load distribution on the dynamic forces exerted on pavement surfaces in terms of various physical parameters characterizing the vehicle-road interaction. The proposed model becomes an axle load model when placed perpendicular to a wheel path; and it can be a half of a vehicle model when placed along a wheel path. Dynamic responses of the models are computed in Excel worksheets in terms of the vehicle characteristics and the characteristics of road profiles. The intensities for both the rates of the dynamic forces and the dynamic forces are evaluated by considering the rotational effect induced by road profiles. It is demonstrated that the pitch & roll motion can change substantially the magnitudes of these dynamic ...

In this study the hydration kinetics of four different types of cements during early ages were in... more In this study the hydration kinetics of four different types of cements during early ages were investigated by both chemical shrinkage and isothermal calorimetry tests. Chemical shrinkage tests were performed at both different temperatures and pressures while isothermal calorimetry tests were conducted only at different temperatures. The hydration kinetics curves at different curing conditions were found to converge reasonably well if properly transformed with a set of scaling factors. Therefore, the experimental hydration kinetics curve at one curing condition can be used to predict that of another curing condition using a single scale factor. The scale factor is similar to the coefficient used to compute the equivalent age of a specified curing condition when applying the maturity method to estimate concrete strength. Its dependence on curing temperature and curing pressure can be modeled by the activation energy and the activation volume of the cement, respectively .

Construction and Building Materials, 2015

ABSTRACT The hydration kinetics of Class H oil well cement with and without chloride accelerators... more ABSTRACT The hydration kinetics of Class H oil well cement with and without chloride accelerators were evaluated via isothermal calorimetry. A series of tests were conducted with two different water-to-cement (w/c) ratios (0.38 and 0.91) at two different temperatures (15 °C and 25 °C). The test results indicate that the effect of different chlorides on the overall cement hydration rate is primarily determined by the molar concentration of the chloride in water and can be simulated by a generalized scale factor model. At concentrations up to 0.9 M Cl−, the overall hydration rate increases approximately linearly with the CaCl2 concentration and shows virtually no dependence on temperature and w/c ratio. In contrast, when NaCl or KCl is used at similar concentrations (up to 0.9 M Cl−), the hydration rate increases linearly with the logarithm of the chloride concentration and the correlation varies slightly with temperature and w/c ratio.

Cement and Concrete Research, 2014

ABSTRACT A series of NMR and isothermal calorimetry tests were conducted to depict a retarder exc... more ABSTRACT A series of NMR and isothermal calorimetry tests were conducted to depict a retarder exchange mechanism whereby a powerful organophosphonate retarder (nitrilotris(methylene) triphosphonate, or NTMP) is replaced by a much weaker phosphate retarder (sodium hexametaphosphate, or SHMP). The retardation of cement hydration by NTMP is believed to be primarily attributed to the dissolution of calcium from the cement and the subsequent precipitation of a layered calcium phosphonate that binds to the surface of the cement grains and strongly inhibits further hydration. The test results from this study show that the addition of SHMP helps to dissolve the precipitated calcium phosphonate and thus removes the strong retardation effect of NTMP. The proposed retarder exchange mechanism may be employed to develop cement systems with a controlled setting behavior.

SPE International Oilfield Nanotechnology Conference and Exhibition, 2012

ABSTRACT Nanotechnology encompasses a wide scope of disciplines and nanomaterials are now being u... more ABSTRACT Nanotechnology encompasses a wide scope of disciplines and nanomaterials are now being used as commercially viable solutions to technical challenges in industries ranging from electronics to bio-medicine. Recently, the application of nanomaterials to solve problems in oilwell cementing has begun to be investigated by several different research groups in the oil and gas industry. The following uses of nanomaterials have been presented by several independent laboratories as possibilities in the oilwell cementing industry: (1) nanosilica and nanoalumina as potential accelerators; (2) nanomaterials including carbon nanotubes (CNTs) with high aspect ratio to enhance mechanical properties; (3) nanomaterials to reduce permeability/porosity; and (4) nanomaterials to increase thermal and/or electrical conductivity. In this paper, a review of the aforementioned application concepts is presented with a focus on understanding the role of multiwall CNTs (MWNTs), nanosilica, and nanoalumina in oilwell cement hydration chemistry. The influence of the integration of MWNTs into oilwell cement on the physical properties of cement is discussed. Results from an isothermal microcalorimetric study are presented to help understand the difference between the mode of acceleration of a typical cement accelerator, like CaCl2, compared to nanosilica and/or nanoalumina.Introduction In recent years, the conceptual framework of nanotechnology has demonstrated utility across a wide variety of industries, from textiles and defense to aerospace and energy. While the materials in these industries can vary greatly, the fundamental concept that a superior and more functional organization of matter is achieved through an intelligent design from the "bottom up?? remains the same. This is no different in the cement industry, where self-sensing, self-healing, self-cleaning, and strength enhancement are concepts now frequently discussed in the research community. The inclusion of nanoscale particles into Portland cement paste, mortar, or concrete can impart functionality into cements yielding a variety of different emergent property enhancements. Generally, nanomaterial induced property enhancements have been observed and reported to include (1) early strength development, (2) increased long-term tensile-to-compressive-strength ratio, (3) viscosity enhancement, and (4) overall increases in the early-stage compressive strength. These modifications and enhancements are attributed to factors such as densification, particle packing, acceleration, high surface area, increased nucleation sites, and structural reinforcement. This paper focuses on the influence of nanoparticles, specifically on the fresh and the hardened properties of the mixture (Senff et al. 2010; Jalal et al. 2012; Khaloo et al. 2011; Leemann and Winnefeld 2007; Hosseini et al. 2010; Ozyildirim and Zegetosky 2010; Gaitero et al. 2010; Shih et al. 2006; Ltifi et al. 2011; Gaitero et al. 2008). In particular, how nanosilica and nanoalumina can act as potential accelerators is investigated. How CNTs with high aspect ratios can enhance the mechanical properties of cements is also discussed. Certain nanomaterials that serve to reduce the cement's permeability/porosity are described, and how some nanomaterials increase the thermal and/or electrical conductivity in cement is briefly addressed.

IADC/SPE Drilling Conference and Exhibition, 2014

IADC/SPE Drilling Conference and Exhibition, 2014

Construction and Building Materials, 2015

ABSTRACT Cement chemical shrinkage under pressure can be measured by an injection pump.•Chemical ... more ABSTRACT Cement chemical shrinkage under pressure can be measured by an injection pump.•Chemical shrinkage increases with increasing temperature during early stage.•Curing pressure up to 13 MPa has relatively little effect on chemical shrinkage.•Hydraulic fracture method may be used to obtain the in-situ strength of well cement.

Construction and Building Materials, 2015

ABSTRACT A variety of different types of oil well cement were tested with a newly developed test ... more ABSTRACT A variety of different types of oil well cement were tested with a newly developed test apparatus under different curing conditions to study the effects of curing temperature and pressure on their tensile test behavior. Specimens were cured at temperatures ranging from 24 to 60 °C and pressures ranging from 0.69 to 51.7 MPa. Tensile tests were performed at the age of 72 h. The capability of the test apparatus to record system deformation during pressurization and depressurization also allows study of cement–water interactions at different curing stages. Both splitting tensile tests and water pressure tensile tests were conducted after depressurization for assessing possible damage induced by the pressure change. A potential damage mechanism of set cement during depressurization is proposed in this study by analyzing the system deformation and tensile strength test data.

Cement and Concrete Research, 2013

ABSTRACT The heat evolution of Class G and Class H oil well cements cured under different tempera... more ABSTRACT The heat evolution of Class G and Class H oil well cements cured under different temperatures (25 °C to 60 °C) and pressures (2 MPa to 45 MPa) was examined by isothermal calorimetry. Curing pressure was found to have a similar effect on cement hydration kinetics as curing temperature. Under isothermal and isobaric conditions, the dependency of cement hydration kinetics on curing temperature and pressure can be modeled by a scale factor which is related to the activation energy and the activation volume of the cement. The estimated apparent activation energy of the different cements at 2 MPa varies from 38.7 kJ/mol to 41.4 kJ/mol for the temperature range of 25 °C to 40 °C, which decreases slightly with increasing curing temperature and pressure. The estimated apparent activation volume of the cements at 25 °C varies from − 23.1 cm3/mol to − 25.9 cm3/mol for the pressure range studied here, which also decreases slightly in magnitude with increasing curing temperature.

ACI Materials Journal, 2012

Cement and Concrete Composites, 2013

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.