Amarasinghe, Widuramina (NORCE Norwegian Research Centre AS, Norway, University of Stavanger, Norway) | Fjelde, Ingebret (NORCE Norwegian Research Centre AS, Norway, University of Stavanger, Norway) | Rydland, Jan-Aage (NORCE Norwegian Research Centre AS, Norway) | Guo, Ying (NORCE Norwegian Research Centre AS, Norway)
When CO2 is injected to aquifers, CO2 will be dissolved into the water phase and react with rock minerals. The CO2 dissolution into the water phase initiated by the diffusion, will increase the density of the water- phase and thereby accelerate convective flow of CO2. The objective of the presented work was to study the effects of permeability and wettability of porous media by visual investigation of mixing of supercritical CO2 (sCO2) with water by convectional flow at realistic reservoir conditions (pressure and temperature). This required construction of a high-pressure transparent 2D-cell that allows visualization of CO2 transport, and development of experimental procedures.
To develop the high-pressure Hele-Shaw 2D-cell, stress/strain calculations and simulations were carried out to select the best building materials for realistic working pressure and temperature and required dimensions to study convection. Porous media was prepared by glass beads of different sizes giving different permeability and wettability. The experiments were carried out at 100 bars and 50 °C using deionized water solution with Bromothymol blue (BTB) as pH indicator.
In the constructed Hele-Shaw 2D-cell, the cell volume was formed by two glass plates separated by an adjustable spacer. The cell thickness was 5.0 mm in the present study. The high-pressure 2D-cell has made it possible to investigate CO2-dissolution and mixing with water at pressures and temperatures realistic for CO2-storage reservoirs.
CO2 mixing and finger development in the water phase without the presence of porous media, was an instantaneous process. The rate for CO2 dissolution and mixing with water was found to increase with increasing permeability for water-wet porous media. The CO2 dissolution pattern was found to depend on the permeability. Fingering of CO2 rich high-density water was observed with the high permeable porous media. Piston-like displacement was observed in lower permeable porous media. No significant effect of wettability was observed in the high-pressure 2D cell experiments. After experiments, it was confirmed that the wettability of the oil-wet particles was changed during the CO2 dissolution experiments.
The goal of this paper was to examine refinery workers’ personal exposure to benzene and 1,3-butadiene and increase awareness of exposure conditions by collaboration with involved refineries. Exposure to airborne agents needs to be assessed in the personal breathing zone by the use of personal measurement equipment. Specific measurement devices for assessing personal exposure to airborne nanomaterials have only become available in the recent years.
To help lower costs of offshore projects, DNV GL has launched initiatives focused on the use of composite components. Researchers at Rice University in Houston are hoping their new theory on composite properties may help the oil and gas industry reduce the time it takes to develop and test new materials.
This paper presents a state-of-the-art review of scale-inhibitor-analysis techniques and describes how these techniques can be used to provide cost-effective scale management. Calcium sulfate (CaSO4) in the form of gypsum and anhydrite is one of the more prevalent evaporite minerals typically found in the carbonate rocks of the western Canadian sedimentary basin (WCSB).
Operators are increasing capital budgets in the wake of tariffs and quotas initiated by the US government on steel imports, and the product exclusion process has revealed a host of other issues. If the tariffs are here to stay, what does industry hope to see moving forward? Supply and Demand in Unconventionals: Where Do Service Companies Fit? Service company executives examine how the oil price downturn affected supply and demand for their services in the unconventional sector, and strategies they have undertaken to stay afloat as operators adjust to uncertainty.
Operators are increasing capital budgets in the wake of tariffs and quotas initiated by the US government on steel imports, and the product exclusion process has revealed a host of other issues. If the tariffs are here to stay, what does industry hope to see moving forward? How will a US steel tariff affect the oil and gas supply chain? Industry criticism points to a noticeable effect on construction expenditure and jobs, but where will the pain be most felt?
The combination will operate and share ownership of midstream gas assets in the Utica and Marcellus Shale plays. CPPIB financially backs operator Encino Energy, which last year acquired Chesapeake Energy’s Utica assets. The high level of dissolved iron commonly present in the Marcellus waters of Pennsylvania and West Virginia adversely affects the ability of scale inhibitor to inhibit calcium carbonate scale.
The Charles F. Rand Memorial Gold Medal is awarded for distinguished achievement in mining administration, including metallurgy and petroleum. If they have received the Anthony F. Lucas Medal or the Robert Earll McConnell Award. If they are a recipient of SPE Honorary Membership. If they have received the Anthony F. Lucas Medal or the Robert Earll McConnell Award. If they are a recipient of SPE Honorary Membership.
The objectives of the present study are to evaluate a zwitterionic surfactant for applicability in EOR. The surfactant was tested in terms of its salt tolerance, thermal stability, interfacial reduction capability, wettability alteration and resistance to adsorption. The effect of salinity and alkalinity was also tested on the above stated physico-chemical properties of the surfactant.
The salt tolerance of the surfactant was tested by testing for precipitation of surfactant solution with increasing salinity at 30 °C and 80 °C. The thermal stability of the surfactant was tested by TGA testing. The interfacial tension of the crude oil and surfactant solution with varying surfactant concentration, salinity and alkalinity was tested by spinning drop technique. The wettability alteration by surfactant solution was tested by measuring contact angle on an oil wet sample. The adsorption study was done by measuring the concentration of surfactant after its solution was exposed to adsorption on crushed rock sample.
The surfactant had salt tolerance of 20% salinity. The surfactant was found stable to 130 °C as per TGA curve. The interfacial tension (IFT) was reduced to ultralow value by surfactant solution for concentration at and above its critical micelle concentration. The presence of salt had minimal effect on the IFT reduction capability of the surfactant solution. Presence of alkali had synergetic effect on IFT reduction. The wettability of the oil wet sample was altered to preferentially water wet by surfactant. The loss of surfactant due to adsorption was found to be within recommenced range for applicability in EOR. These excellent physico-chemical properties of the zwitterionic surfactant suggest that it can be used in the mature oil fields for recovery of trapped oil.
Foaming in absorber column for sour gas treatment using amine is a common problem which adversely affects column performance leading to reduction in sales and fuel-gas production and solvent loss. Mostly antifoam injection has been a common method to counter the foaming, large dosage and frequent dosing of antifoam many a times aggravates the problem. This study details an alternative technique based on pressure pulse mechanism to control foaming in one of ONGC's gas sweetening plants.
One of ONGC's amine based sour gas sweetening plants faced severe foaming problem frequently. The feed rate is 200 kscm/hr and absorber column operating pressure is 51 kg/cm2. The experiment utilizes the property of surface tension which fluctuates with change in pressure of the system leading to foam collapse. The experimental procedure involved varying the sour gas feed rate, thereby creating pressure pulse inside the absorber column. Differential pressure across the column which is an indicator of foaming tendency is then monitored and controlled within 1.0 kg/cm2 and recorded for establishing effectiveness of the method.
It is observed that by providing a number of cycles of pressure pulse in the absorber, the differential pressure stabilizes gradually which indicates collapse of foam. It shows that whenever there is increase in feed, expansion of bubble takes place which provides high interfacial liquid-vapour contact. On the other hand whenever there is decrease in feed rate, compression of bubble takes place which provides low interfacial liquid-vapour contact. Surface layer surrounding the bubbles in a foam acts as a membrane or skin that can stretch or relax in response to change in pressure and gives a mechanical shock which breaks the bubble. The increase of size ultimately leads to instability and break-up of the upper surface and releases the liquid holdup. Hence by using feed rate spikes, the pressure of the bubble is pulsed to higher levels and returned to substantially the original level. This cycle continues for a selected number of times so that this pressure pulse travels through the liquid and bubbles and affects its surface tension. This results into a transition phase which in very high energy level breaks the bubble and releases the gas and decreases the liquid hold up and controls the foaming phenomenon.
This paper will gives an insight into a novel methodology of mitigating foaming problem in a sour gas treating absorber just by varying the feed rates in a controlled manner. This technique eliminates the need for injecting antifoam agents which in turn will reduce the operating expenditure of the plant. Adverse impact on environment due to excessive use of antifoam agent is also minimized.