A surface TSC study of the interaction between a gas and an epoxy resin

Gas migration through cement columns has been an industry challenge for many years. Formation gas/influx can migrate through the cement column resulting in gas being present at the surface. To overcome gas migration on existing wells, remedial jobs are executed, which requires detailed engineering and testing prior field deployment. The objective of this paper is to detail the effort and experimental work that took place to use different polymer resin systems in Saudi Arabia gas wells. The two polymer resin systems are differentiated by their main component, either epoxy resin or polyester resin. The epoxy resin system is prepared by mixing an epoxy resin with an aromatic amine curing agent while the polyester resin system is prepared by mixing polyester resin with norpol peroxide curing agent, filler, and silicon dioxide. This study is the first to assess the performance of two different types of polymer resin systems and evaluate their remedial operations according to the authors’ best knowledge. In addition, this paper discusses operational challenges that may occur when using each type of polymer resin system. Lab tests were conducted to measure the thickening time, the rheological properties, compressive strength, and limitations for each polymer resin system. The tests suggest that a maximum temperature of 225°F and 275°F should be maintained when using the epoxy and polyester polymer resin systems, respectively. Based on the study, the epoxy resin system is easier to control as it is composed of only two components unlike the polyester resin system, which is comprised of several components. The lab study suggests operational recommendations to increase the probability of success of the polymer resin systems.

The rapid growth of Carbon Dioxide (CO2) and/or Nitrogen (N2) Enhanced Oil Recovery (EOR) projects has resulted in the need for efficient low cost rejection technology. This is particularly true if the Nitrogen or Carbon Dioxide is produced with a natural gas that has an existing market. Basic rejection cycles are described and compared. Key process and mechanical design considerations, especially those unique to Nitrogen and Carbon Dioxide, are emphasized. The Carbon Dioxide or Nitrogen content in the produced gas increases with time over the life of a project, so the rejection equipment must perform satisfactorily over a broad range of feed compositions. Recycling the rejected Carbon Dioxide or Nitrogen is a cheaper source of injection gas than its original source. A rejection unit can be designed as an add-on unit to existing natural gas processing facilities in which much of the stabilization, pre-treatment, and liquid recovery already exists. A sample application for nitrogen rejection is presented including process performance and simple economics for a "typical" case.

POSS/EHTPB synergistically toughened epoxy resin for cryogenic application

Binary gas adsorption/desorption isotherms: effect of moisture and coal composition upon carbon dioxide selectivity over methane

OPTICAL FIBRE EVANESCENT WAVE CURE MONITORING OF EPOXY RESINSG. R. Powell, P. A. Crosby, G. F. Fernando#, C. M. France, R. C. Spooncer', D. N. Waters*.Brunel University, Department of Materials Technology, Kingston Lane, Uxbridge, Middlesex, UB8 3PH, UK.*Department of Manufacturing and Engineering Systems, Department of Chemistry.#To whom correspondence should be addressed.ABSTRACTTwo types optical fibre sensors (OFS) were investigated for use in monitoring the cure of an epoxy-amine resin system: (i)an evanescent wave sensor and (ii) a refractive index sensor. The evanescent wave sensor was used to detect changes inconcentration of the active chemical species involved in the cure reaction via evanescent wave near-infrared spectroscopy.By using the optical fibre as an attenuated total reflection waveguide, spectra were collected over the range 1490-1570 nmat regular time intervals during the cure. This technique enabled the depletion of amine to be monitored. Results obtainedvia this method were fitted to kinetic models which allowed prediction of the reaction rate at different cure temperatures andconversions. The optical fibre evanescent wave sensor results were compared with data obtained using an established curemonitoring technique (FT-IR spectroscopy).A theoretical model of the evanescent sensor has been used which describes the relationship between evanescent absorptionas a function of absorber concentration and refractive index. Predictions of sensor response were undertaken using absorptiondata from FT-JR spectroscopy and refractive index results as a function of cure time. The predicted sensor response was thencompared with experimentally obtained sensor data.An optical fibre sensor which monitored the cure process via refractive index change was also investigated. Sensors wereset up to allow simultaneous collection of data during cure from the OFS, together with data from transmission near-infraredspectroscopy and Abbe refractometry. In this way the response of the sensor to changes in the cure state of the resin,refractive index and temperature were compared.Keywords: optical fiber sensors, cure monitoring, epoxy resins, evanescent wave, near-infrared spectroscopy, refractometry.1. INTRODUCTIONEpoxy resin and amine hardener systems are used extensively in advanced fibre reinforced composites (AFRC). Themechanical properties of AFRC are generally dominated by the properties of the reinforcing fibres, however, the matrix-dominated properties can be affected by the crosslink density of the resin system used. The crosslink density is in turninfluenced by the chemical state of the resin before cure (including the moisture content) and the processing conditions usedto cure the resin'. It is therefore attractive to have a cure sensor which can determine the state of cure of a compositecomponent at locations remote from the composite surface and which will not affect the integrity of the finished componentafter processing.To date, many in-situ techniques have been employed to monitor the state of cure of a composite or resin system. Theseinclude electrical resistance and dielectric analysis2, ultrasonic wave propagation3 ,

Carbon dioxide and nitrogen have both proven to be useful aids in will stimulation. Laboratory data are presented showing the effect of carbon dioxide on foaming agents, corrosion, reaction rate of hydrochloric acid, fluid-loss additives and clay swelling. Carbon dioxide is generally beneficial for all of these except the fluid-loss additives. The corrosion rate of carbonated water is very low compared to inhibited hydrochloric acid. A chart of the viscosity of carbon dioxide is presented. If is estimated that carbon dioxide can reduce friction loss of oil-base fluids by 29 to 60 per cent. Individual field results and conclusions from other summaries are presented. Both nitrogen and carbon dioxide are effective in removal of stimulation fluids. Carbon dioxide has proven useful in removing water or emulsion blocks. Introduction The use of nitrogen and carbon dioxide in well stimulations has grown rapidly in the past two years. The uses and advantages of these gases have been described previously for well stimulation, testing and cementing programs. Because of the differences in physical and chemical properties between nitrogen and carbon dioxide, one gas is usually better suited than the other for a specific application. Generally speaking, nitrogen is superior in low injection rate applications and when precise volume control is critical. Carbon dioxide, on the other hand, is better adaptable to high rate fracturing and acid treatments. Gases were introduced to the oil and gas industry primarily as an aid to recovery of stimulation fluids. This application still accounts for the major usage of nitrogen and carbon dioxide. Special applications, however, which utilize specific properties of the gases, are being discovered continually. The development of these methods is opening the door to better controls over well performance. Effect of a Foaming Additive with Nitrogen and Carbon Dioxide By the nature of the solubility-pressure relationship of carbon dioxide, an induced solution-gas-drive mechanism is created when the pressure is lowered and the gas comes out of solution. To demonstrate this effect the apparatus shown in Fig. 1 was constructed. The 160-cc cell was filled to 100 cc with the fluid to be tested, a gas pressure (nitrogen or CO2) of about 800 psi was applied and allowed to come to equilibrium. The valve was then opened and the amount of liquid carried over was measured in a graduated cylinder. These tests were also conducted using various amounts of foaming additive to see if the additive would enhance the recovery. The results of these tests are given in Table 1. As expected, the recovery of fluids was substantially greater when using CO2 than when using nitrogen. For example, at 80F the recovery with CO2, and no foaming additive was 40 per cent, while with nitrogen it was essentially zero. The addition of the foaming agent increased the recovery substantially. With CO2 the recovery increased from 40 per cent to 70 per cent when 0.2 per cent foaming additive was used.

The permanent crosslinked network imparts chemical and mechanical stability to crosslinked elastomers, making their recycling a serious environmental issue. The decomposition products of pentaaryl diazoxide in the structure of hydantoin epoxy resin are nitrogen and carbon dioxide, and it is an environmentally friendly resin material. Here, we demonstrate a reversible covalent bonding reaction catalyzed by Zn2+ between the ester bond formed by the hydantoin epoxy resin and the acid anhydride, and construct a reversible crosslinked network structure of the environmentally friendly acid anhydride/hydantoin epoxy resin material. The strength, hardness and toughness of the cured material are greatly improved by optimizing its ratio. The ester exchange bonding can be reversible with temperature, which leads to the shape memory capability of the synthesized cured material. The cured product of HMY1 was recovered with ethylene glycol and completely dissolved at 180°C for 11 h. Ethylene glycol was volatilized at 190°C to obtain decomposed epoxy oligomer (DEO), which was added to the HMY1 resin system (the amount of DEO was 30 wt% of the total mass of the resin), and the network structure was cross‐linked to enable it to be recovered and remanufactured. Thus, this work provides a new avenue for the environmentally friendly development of recyclable, reconfigurable, and thermally adaptable shape‐memory hydantoin epoxy materials.Highlights Hydantoin epoxy resin eventually breaks down into non‐toxic CO2 and N2. Hydantoin epoxy and methyl tetrahydrophthalic anhydride form a reversible dynamic chemical bond catalyzed by Zn2+. Ethylene glycol can recover and reuse the solidified product.

Using nitrogen and carbon dioxide as cushion gases can bring economic profit due to their cheap costs. However, the different properties of these gases cause differences in behavior when operating in underground gas storage (UGS). In particular, the mass density of nitrogen gas is similar to methane, while carbon dioxide is much heavier than methane in reservoir conditions. These differences cause loss of inert gas or productivity to vary. From this perspective, it is crucial to analyze the behavior of nitrogen and carbon dioxide during the operation of UGS reservoir. The purpose of this study is to evaluate loss of inert gas of injected gas and to determine productivity according to different cushion gases. A simulation research was performed to compare the effects of nitrogen and carbon dioxide and their behavior. The results showed that nitrogen has less loss of inert gas than carbon dioxide, but reduced productivity compared with carbon dioxide.

The objective of this study was to examine the effects of soil moisture, irrigation pattern, and temperature on gaseous and leaching losses of carbon (C) and nitrogen (N) from soils amended with biogas slurry (BS). Undisturbed soil cores were amended with BS (33 kg N ha−1) and incubated at 13.5°C and 23.5°C under continuous irrigation (2 mm day−1) or cycles of strong irrigation and partial drying (every 6 weeks, 1 week with 12 mm day−1). During the 6 weeks after BS application, on average, 30% and 3.8% of the C and N applied with BS were emitted as carbon dioxide (CO2) and nitrous oxide (N2O), respectively. Across all treatments, a temperature increase of 10°C increased N2O and CO2 emissions by a factor of 3.7 and 1.7, respectively. The irrigation pattern strongly affected the temporal production of CO2 and N2O but had no significant effect on the cumulative production. Nitrogen was predominantly lost in the form of nitrate (NO3−). On average, 16% of the N applied was lost as NO3−. Nitrate leaching was significantly increased at the higher temperature (P < 0.01), while the irrigation pattern had no effect (P = 0.63). Our results show that the C and N turnovers were strongly affected by BS application and soil temperature whereas irrigation pattern had only minor effects. A considerable proportion of the C and N in BS were readily available for soil microorganisms.

Diffusivity is a strong function of concentration and an important transport property. Diffusion of multiple species is far more frequent than the diffusion of one species. However, there are limited experimental data available on multi-component diffusivity. The objective of this study is to develop an optimal control framework to determine multi-component concentration-dependent diffusivities of two gases in a non-volatile phase such as polymer. In Part 1 of this study, we derived a detailed mass-transfer model of the experimental diffusion process for the non-volatile phase to provide the temporal masses of gases in the polymer. The determination of diffusivities is an inverse problem involving principles of optimal control. Necessary conditions are determined to solve this problem. In Part 2 of this study, we utilized the results of Part 1 to determine the concentration-dependent, multi-component diffusivities of nitrogen and carbon dioxide in polystyrene. To that end, solubility and diffusion experiments are conducted to obtain necessary data. In the ternary system of nitrogen (1), carbon dioxide (2), and polystyrene (3), the diffusivities and D11, D12, D21, and D22 versus the gas mass fractions are two-dimensional surfaces. The diffusivity of carbon dioxide was found to be greater than that of nitrogen. The value of the main diffusion coefficient D11 was found to increase as the concentration of carbon dioxide increased. The highest value of D11 obtained was 2.2 X 10^-8m^2s^-1 for nitrogen mass fraction of 3.14 X10^-4 and for a carbon dioxide mass fraction of 5.67 X 10^-4 . The cross-diffusion coefficient increased as the concentrations of nitrogen and carbon dioxide increased. The diffusivity reached its maximum value when the concentrations of nitrogen and carbon dioxide were at their maximum values. The diffusivity was of the order of 10^-9m^2s^-1. The diffusivity of the cross-diffusion coefficient D21 was found to be increased for the mass The diffusivity of the cross-diffusion coefficient was found to be increased for the mass fractions of carbon dioxide ranging from 0 to 1.70 X 10^-3 . The diffusivity was found to be of the order of . The diffusion coefficient, D22, was found to increase with the concentrations of nitrogen and carbon dioxide, D22 remained high with low concentrations of carbon dioxide. The diffusivity was found to be of the order of 10^-7m^2s^-1

Diffusivity is a strong function of concentration and an important transport property. Diffusion of multiple species is far more frequent than the diffusion of one species. However, there are limited experimental data available on multi-component diffusivity. The objective of this study is to develop an optimal control framework to determine multi-component concentration-dependent diffusivities of two gases in a non-volatile phase such as polymer. In Part 1 of this study, we derived a detailed mass-transfer model of the experimental diffusion process for the non-volatile phase to provide the temporal masses of gases in the polymer. The determination of diffusivities is an inverse problem involving principles of optimal control. Necessary conditions are determined to solve this problem. In Part 2 of this study, we utilized the results of Part 1 to determine the concentration-dependent, multi-component diffusivities of nitrogen and carbon dioxide in polystyrene. To that end, solubility and diffusion experiments are conducted to obtain necessary data. In the ternary system of nitrogen (1), carbon dioxide (2), and polystyrene (3), the diffusivities and D11, D12, D21, and D22 versus the gas mass fractions are two-dimensional surfaces. The diffusivity of carbon dioxide was found to be greater than that of nitrogen. The value of the main diffusion coefficient D11 was found to increase as the concentration of carbon dioxide increased. The highest value of D11 obtained was 2.2 X 10^-8m^2s^-1 for nitrogen mass fraction of 3.14 X10^-4 and for a carbon dioxide mass fraction of 5.67 X 10^-4 . The cross-diffusion coefficient increased as the concentrations of nitrogen and carbon dioxide increased. The diffusivity reached its maximum value when the concentrations of nitrogen and carbon dioxide were at their maximum values. The diffusivity was of the order of 10^-9m^2s^-1. The diffusivity of the cross-diffusion coefficient D21 was found to be increased for the mass The diffusivity of the cross-diffusion coefficient was found to be increased for the mass fractions of carbon dioxide ranging from 0 to 1.70 X 10^-3 . The diffusivity was found to be of the order of . The diffusion coefficient, D22, was found to increase with the concentrations of nitrogen and carbon dioxide, D22 remained high with low concentrations of carbon dioxide. The diffusivity was found to be of the order of 10^-7m^2s^-1

7 - Fabrication and Properties of Liquid Resin and Monomer-Modified Systems

Well RXY is located in the Ravva offshore field in the Krishna-Godavari basin (India) and was intended to produce significant crude from a secondary reservoir section. This paper presents a case study concerning rigless remediation of microchannels in the cement packer (placed in the annulus of the production tubing and casing to isolate the producing zone) and discusses laboratory development of a customized epoxy resin system, simulations to estimate channel size, three-dimensional (3D) displacement modeling, drillout after placement, and evaluation post-placement. An epoxy resin system was selected to seal micro-annuli in a cement packer and restore zonal isolation because of its ability to develop high compressive strength, potential to resist significant strain, and its solids-free formulation. This resin system was pumped followed by an ultrafine cement slurry comprising a fine-particle high-surface-area cement blend that can penetrate small channels more easily compared to conventional cement. The top of fluids was simulated for various cases as per channel size estimations, and 3D displacement modeling was performed to incorporate fluid contamination. The strategic placement of epoxy resin and ultrafine cement focused on isolating annuli above the zone of interest. Conventional cement testing equipment was used to customize resin formulations to downhole conditions. After placement and solidification of the designed treatment, cement remaining in the tubing was successfully milled. A positive hermetical test was conducted after 48 hours of setting time, and the result was confirmed as successful. Barrier evaluation was performed using a combination of a cement bond log (CBL) tool and ultrasonic scanner. Furthermore, the acoustic impedance was post-processed to generate a derivative acoustic impedance (DZ) data set before performing the data analysis workflow. On the basis of analysis of this evaluation, the well was perforated in the pay zone interval and produced approximately 2,000 BOPD. The well was observed for several days to confirm tubing and casing isolation. The epoxy resin plus ultrafine cement blend was designed to deliver a dependable barrier. This engineering solution proved to be a highly efficient and cost-effective method for treating narrow cement channels in a deviated tubing-production casing annulus using only pressure-balanced cement placement. The epoxy resin technology has unique properties that make it best suited for remediation, particularly in tight geometries, such as in the current scenario of micro-annuli channels in a cement sheath. The resin system is solids-free (Newtonian fluid) and can provide a high-pressure seal. The system also withstands contamination (overcomes inefficient well fluid displacement), which is beneficial when prejob cleanup resources are limited. In addition, this drillable system develops compressive strength ranging from 5,000 to 15,000 psi.

The aim of the study is to determine the optimum cure temperatures and kinetics for two different epoxy resin systems without using solvent. Two resin systems consist of EPIKOTE 828® epoxy resin–EPIKURE® 3090 polyamidoamine curing agent and DURATEK® KLM 606A epoxy resin–DURATEK® KLM 606B polyamide curing agent. The ratio of resin to curing agent was kept as 1:1 for both the systems. Curing temperatures of both the systems were determined and kinetic parameters were calculated with respect to the experimental results following nth‐order kinetics. Then, a series of isothermal temperatures was applied to the resin systems in order to assess the cure process in terms of conversion, time, and temperature by using differential scanning calorimeter (DSC). The test results of both systems show that the rate of degree of cure for EPIKOTE 828® epoxy resin–EPIKURE® 3090 polyamidoamine curing agent system is approximately 10 times higher than that of DURATEK® KLM 606A epoxy resin–DURATEK® KLM 606B polyamide curing agent system at 230°C. POLYM. COMPOS., 28:762–770, 2007. © 2007 Society of Plastics Engineers

Synergistic effect between melamine cyanurate and a novel flame retardant curing agent containing a caged bicyclic phosphate on flame retardancy and thermal behavior of epoxy resins