Gas Extraction Wells Research Articles

APPLICATION OF THE ELECTROCHEMICAL TREATMENT METHOD FOR THE REMEDIATION OF PETROLEUM HYDROCARBONS FROM CONTAMINATED SOILS

Contaminated soils with toxic and persistent pollutants pose significant potential hazards to the environment and human health. The problem of polluted soils and choosing the most appropriate remediation strategy is a current concern throughout the world. As a result of the industrial activities related to the energy sector (mainly from the extractive industry), the contaminants of interest at the national and international level in terms of the remediation of contaminated sites are petroleum hydrocarbons. In this context, the main aim of the present research was to evaluate the degree of remediation of these contaminants during the application of the electrochemical remediation method. The soil contaminated with crude oil, subject to remediation, is from Teleorman county, Siliștea commune, an area where oil and natural gas extraction wells are located. Following the application of the electrochemical process, a decrease in the TPH concentration level was observed from an initial concentration of 5000 mg/kg s.u. to 2228 mg/kg s.u., thus obtaining a 55% remediation percentage, after a period of 14 days. Consequently, it can be appreciated that the electrochemical process applied in order to remediate a soil contaminated with petroleum products is advantageous in terms of the short duration of time, but the method also presents some disadvantages such as energy consumption and implicitly significant related costs.

Understanding landfill gas behavior at elevated temperature landfills

Landfill gas (LFG) wellhead data were compared to understand the range of observations due to unique conditions at five elevated temperature landfills (ETLFs) in the U.S. Correlations of the primary gas ratio, CH4:CO2, show distinct compositional indicators for (1) typical operation, (2) subsurface exothermic reactions (SERs), (3) high moisture content, and (4) air intrusion that can help operators and regulators diagnose conditions across gas extraction wells. ETLFs A, B, D, and E showed similar trends, such as decreasing CH4 and increasing CO2, CO, and H2 that have been previously described. ETLF C uniquely exhibited elevated CH4 and temperatures simultaneously due to carbonation (i.e., CO2 consumption) of a steel slag which was used as alternative daily cover (ADC). At the maximum gas well temperature, T = 82 °C/180 °F, CH4 and CO2 concentrations were 47% and 28%, respectively. At ETLFs A, B, and E, H2 > 50% were regularly observed in affected gas wells for several years. At the five ETLFs, maximum CO concentrations ranged from 1400–16,000 ppmv. Like the analysis of CH4:CO2, it is hypothesized here that H2 (%):CO (ppmv) may infer the types of waste that are thermally degrading. Co-disposal of industrial wastes and MSW and the use of potentially reactive ADCs should remain an important consideration for landfill operators and regulators because of their potential long-term impacts to LFG quality.

Influence of the top pressure on water removal from a vertical tube in a two-phase flow regime

The purpose of this work is to highlight the effects of wellhead pressure on the removal of water from its bottom. Tests were therefore carried out in a simulation laboratory on a test section represented by a vertical tube 600 mm long and 37 mm in diameter. It was therefore a question of working on a two-phase flow with air as gas and water as liquid. The velocity of the air injected into the tube was calculated taking into account the top and bottom pressures of the vertical tube. Related measurements and calculations were carried out and conclusions were drawn on the impact of the tube top pressure on the removal of water from the tube bottom, all by analogy to vertical gas extraction wells.

Land subsidence due to natural gas extraction in the Thrace basin (NW Turkey) and its influence on the North Anatolian fault under the Marmara Sea

We map surface deformation in the Thrace region of Turkey using the Sentinel-1 Synthetic Aperture Radar (SAR) data. Interferometric Synthetic Aperture Radar (InSAR) time series analysis of the SAR data acquired between 2014 and 2020 on ascending and descending orbits reveals large-scale subsidence (~110 × 60 km) with rates reaching up to 10 ± 1.5 mm/yr. We relate this deformation to natural gas reservoir operations, such as gas exploitation and extraction activities that have been taking place in the region for decades, an inference being supported by the strong correlation between the InSAR time series and the variation in natural gas production during the same time period in the Thrace region reported by the Energy Market Regulation Authority of Turkey. Assuming that the observed subsidence is caused by compaction of sediments in the natural gas reservoirs, we construct a triangulated surface enveloping roughly at the bottom of the gas extraction wells and use it to invert the amount of negative opening (hence volume loss) on triangular elements that are assumed to be buried in an elastic and homogeneous medium. Coulomb stress changes caused by this volume change on the North Anatolian Fault at the Sea of Marmara are found to be insignificant (less than 10?5 Mega-Pascal) to perturb the state of the stress around the Marmara seismic gap. Yet, the large-scale subsidence revealed in this study needs to be taken into consideration when assessing hazards for the infrastructures, settlements, and other engineering structures, particularly in case of a large earthquake in the Marmara Seismic Gap.

The Mathematical Modeling of the Flow Variation of Natural Gas Extraction Wells Depending on the Diameter of the Mixing Pipe

The exploitation of natural gas deposits also requires the transport of the extracted fluids through pipelines to their treatment facilities. Usually the extracted fluids contain, in addition to methane, ethane, liquid fractions of propane, butane, hexane and sometimes salt water associated with the deposit. Given that the delivery of natural gas for consumption must be carried out without water and oil liquids, the flow rates of the gas extraction wells are taken in two-phase mixing pipelines and transported to a single treatment facility. The article presents the impact of the diameter of the mixing pipes on the gas flow

Mathematical Modeling of the Flow Variation of Natural Gas Extraction Wells Depending on the Diameter of the Mixing Pipe

Mathematical Modeling of the Flow Variation of Natural Gas Extraction Wells Depending on the Diameter of the Mixing Pipe

Some findings on the spatial and temporal distribution of methane emissions in landfills

The purpose of this article is to present some facts of interest for the quantification of gas emissions in active landfills obtained from a series of field campaigns in a case study landfill where spatial and temporal patterns of methane emissions were analyzed. Nine campaigns were carried out to measure diffuse surface methane emissions at an European municipal waste landfill in operation using the static flow chamber technique in different seasons over three years. Results obtained show a global annual diffuse flux of 733.26 t CH4/year for the year 2020. Certain points on the surface, where concentrations reached values above 1000 ppm, were observed during the campaigns. These points, called “hotspots”, represented only 10% of all the points measured but accounted for 73% of the total diffuse methane emissions (506 t CH4/year). Furthermore, localized emissions, such as those from landfill gas extraction wells, which were not connected to the general extraction network, were also analyzed. These localized emissions represent more than twice the total diffuse emissions measured on the surface (1500 t CH4/year). These results highlight the importance of identifying high emission points to design effective mitigation measures. Moreover, the influence of certain meteorological conditions such as atmospheric pressure, temperature or rainfall was also studied. A new particular effect has been detected regarding precipitation, which favors or hinders methane emissions depending on the volume accumulated during the previous weeks. Pressure was found to be the factor that most affects methane emission variations in the case studied, presenting a clear inverse correlation with the field data that was collected. This suggests the need to consider the meteorological fluctuations over time to calculate the field emission estimates. Correcting the annual estimation in the case studied by considering the atmospheric pressure fluctuations over the year led to a 14% change in the estimate, obtaining a final result of 836.73 t CH4/year for the total diffuse emissions.

Assessment of in situ properties of municipal solid waste with a large-diameter borehole method.

A Municipal Solid Waste Borehole Assessment (MBA) was developed to assess in situ geotechnical properties of municipal solid waste (MSW) during the boring of gas extraction well construction. A Large-Diameter Borehole Caliper (LDBC) was lowered into the borehole to measure the diameter and record the condition of the wall by time-lapse video photography. The results indicated that the borehole experienced significant radial compression with depth following completion. Radial compressions amounted to approximately 7.5% at 9.14 m, 10% at 21.3 m and 11% at 27.4 m below ground surface. The bulk modulus was estimated by using the captured volumetric strains and reported lateral earth coefficients, and the results showed that it increases with increasing depth. For MSW, the bulk modulus increased up to 13.4 MPa in a linear trend with depth. The unit weights of MSW were obtained using three diameter readings from LDBC, auger barrel outside diameter and outer cutting bit outside diameter. The results showed that the diameter based on outer cutting bit yielded realistic unit weights (5.08-9.68 kN m-3) due to unrealistic calculated saturations by other two assumed diameters. The borehole assessment with LDBC was shown to be an efficient and valuable means for characterising MSW and effectively designing gas extraction wells. The research provided a means to assess the waste mass with accuracy at great depths by directly observing and measuring borehole condition.

Investigation of fugitive methane and gas collection efficiency in Halton landfill in Ontario, Canada.

Methane gas is one of the significant contributors to global warming. A large portion of methane emissions comes from landfills. Developing reliable measurement methods for methane emissions from landfill sites has become very important. In this paper, the surface emissions of methane gas are quantified using a portable probe having a flame ionization detector (FID), a method proven to be successful in landfill gas measurement. Surface methane emissions from two closed cells in the Halton landfill in Ontario, Canada, were measured using the FID method. By analyzing the emissions within the perimeter of the landfill, hotspots of gas leakage were identified. The closed cells in the Halton landfill are equipped with gas extraction system for flaring and energy recovery and a clay topsoil cover. Emission concentrations of fugitive methane were found to range from 0.1 to 63ppm. The largest emissions were detected in locations next to the leachate extraction manholes and malfunctioning gas extraction wells. The landfill gas balance showed that the landfill gas recovery efficiency was 44%, resulting in an average amount of fugitive methane from the landfill of 6124m3/day. The results of the study were used to determine the methane generation potential (Lo) for municipal solid waste to further calibrate the USEPA LandGEM model for Ontario landfills. The model was calibrated by actual methane emission measurement and recovery data. The calibrated Lo was found to be 70m3/t, which is lower than the estimated values in previous studies.

Triboelectric energy harvesting in harsh conditions: Temperature and pressure effects in methane and crude oil environments

Abstract Environmental and safety sensing is becoming increasingly important in the oil and gas industry. However, present solutions to feed theses sensors are expensive and dangerous and there is so far no technology able to generate electrical energy in the operational conditions of oil and gas extraction wells. Here, we show that triboelectric nanogenerators (TENGs) can withstand and harvest energy in harsh conditions. TENGs are a new technology able to efficiently harvest mechanical energy from the environment. By conducting thorough experiments in methane and crude oil over large ranges of pressures and temperatures, we were able to extend the operation realm of TENGs. By independently varying temperature (25–80 ∘C) and pressure (28–119 bar) in methane, we demonstrate that temperature is the most critical parameter for TENGs operating in harsh environments. Furthermore, energy harvesting experiments performed in crude oil reveal a decrease of the electric outputs with increasing crude temperature and pressure. Nevertheless, the assembled device continued to generate electrical energy up to pressures of 830 bar and temperatures of 120 ∘C. This study clearly demonstrates the suitability of triboelectric devices to harvest energy in harsh environments opening a wide new range of possible applications.

NATURAL GAS POTENTIAL OF LAND FORMATION IN UKRAINE

The analysis of the potential of natural gas resources of gas prospective shale formations in the main oil and gas basins of Ukraine, that is of Eastern, Western, Southern ones. On the basis of economic and mathematical modeling of geological and economic characteristics of shale formations, from which successful shale gas mining is currently being carried out in the world, correlation-regressive dependencies have been established. They allow to carry out a predicted estimation of the gas content, the initial rate of gas extraction wells, the marginal cost limit, at which a break-even production of natural gas from shale formations is possible. Using these dependencies, an analysis of the resource potential of slate formations has been carried out and it has been established that in the Eastern region stratigraphic complexes with promising shale formations are included: Devonian deposits - Upper Devonian (Famensian tier); coal deposits - Lower Carboniferous Complex (Tourney, Viseu, Serpukhov Tiers); middle-complex complex (Bashkir and Moscow tiers); Carboniferous complex (Kasimovsky and Gzhel tiers). Yevgenivsko-Druzhelyubivsk, Mirgorod-Livensk, Borkivsk-Velikzagorivsk and Zachipelsk-Livensk areas are the most investments-attractive in the prospects for shale gas extraction in the Eastern region. In the Western region, prospective stratigraphic complexes include deposits of the Cambrian, Silurian and Oligocene-Miocene age. The most investment attractive for shale gas extraction in the Western region is Davydivsky, Rava-Russkaya, East-Lishinskaya and Oleska districts. In the Southern region, perspective shale gas extraction is the deposits of the Middle Jurassic, the upper part of the Visean tier and the lower part of the Serpukhov tier of the carbon fiber of the Pre-Dobrug Trough. The results obtained can serve as a basis for investors to select priority objects for the development of natural gas resources from shale formations in Ukraine.

INFRASOUND AND LOW FREQUENCY NOISE IMMISION FROM PIPELINES. iMPROVING THE ISO 1996-2:2017 PROPOSED METHODS. CASES STUDIES CONDUCTED AT LOS ANDES AND PERUVIAN RAINFOREST

The gas extraction wells are in Amazonian rainforest and by them there are their industrial facilities. The pipeline has about 800 km with four pumps stations and two compressor stations. The challenge of conducting sound measurements was important-there is no specialized literature-and other noise "sources" are howler monkeys, cicadidae chirping, woodpeckers, trees´foliage, etc. However the problem is simply because those fixed industrial facilities are the only ones. People live in isolated hamlet on the side of dirt roads, so they are exposed 24/7 to the continuous noise; at homes 4 km away from the plants the sound level is 60 dBC, but in the spectrum of ILFN tones could not be identified. This Paper presents the procedures that were developed to identify the ILFN tones, improving the methods proposed in ISO 1996-2, writing a software that "automatically eliminates" the sound levels that don´t belong to the industry,

Development of a pore gas pressure transducer used in unsaturated soils at high water content

Pore gas pressure in soil is an important parameter in many geoscience applications such as evaluating the effects of trapped pore gas pressure on water infiltration through soil mass, optimizing the design of gas extraction wells in landfills and assessing the performance of landfill covers in reducing landfill gas emission. In addition, it has been observed that pore gas pressure affects slope stability in unsaturated soils. However, the pore gas pressure build-up induced by water infiltration is generally ignored in most slope stability analysis by assuming gas pressure to be zero. Therefore, pore gas pressure measurement in soils is crucial to better understand the unsaturated soil behaviour. However, most of current measuring techniques of pore gas pressure are affected by water interruption during the measurement in unsaturated soils, especially at high water content. In this study, a novel gas pressure transducer was developed to measure the pore gas pressure in unsaturated soil within a wide range of water content. The newly developed pore gas pressure transducer mainly consists of an electrical pressure sensor package and an integrated membrane filter which can prevent water leaching through the membrane but allow gas to pass it freely. The performance of the gas pressure transducer was evaluated by a series of permeation tests. The results show that the developed gas pressure transducer has a good repeatability to monitor gas pressure and has a relatively fast response to the gas pressure change in compacted soils. This transducer is able to measure pore gas pressure range of 0~50 kPa of soils within a relatively high range of soil water content.

BIOESTIMULACIÓN Y BIORREMEDIACIÓN DE RECORTES DE PERFORACIÓN CONTAMINADOS CON HIDROCARBUROS

The drilling of wells for extracting natural gas generates large quantities of drill cuttings contaminated with hydrocarbons. The use of bioremediation methods can reduce the concentration of hydrocarbons in these materials to an acceptable level. Three soils from the central and north zones of the state of Tamaulipas, Mexico, were assayed by mixing them with drill cuttings contaminated with hydrocarbons to find out the ability of soil to perform the bioremediation of hydrocarbons impregnated in the drill cuttings. The biostimulation of soil microorganisms with N and P on the decomposition of hydrocarbons in these mixtures was evaluated. Mixtures of soil and drill cuttings contaminated with hydrocarbons from natural gas extraction wells were poured and incubated in bioremediation cells of 1.0 × 1.2 × 0.4 m for one year. The rate of soil:drill cuttings in these mixtures was 1:1.5. Two agricultural soils and one soil of natural vegetation were studied. Based on the organic carbon content in the mixtures, N and P (urea and monoammonium phosphate) were added, in sufficient amounts to induce a ratio C:N:P of 100:10:1 in the mixture. The hydrocarbons concentration decreased significantly when the drill cuttings, mixed with soil, were incubated in the cells with addition of N and P, reaching 3000 mg/kg of total hydrocarbons, which is the maximum limit allowed in the agricultural soils by the official Mexican standard NOM-138-SEMARNAT/SSA1-2012. Plants of corn ( Zea mays ) were developed in bioremediated cuttings. The studied soils induced decomposition of hydrocarbons impregnated in drill cuttings and therefore allowed for the bioremediation of cuttings. Biostimulation of soil microorganisms with nutrients N and P, humidity and aeration increased the decomposition of hydrocarbons and fostered the bioremediation of drill cuttings.

Disequilibrium of Naturally Occurring Radioactive Materials (NORM) in Drill Cuttings from a Horizontal Drilling Operation

Naturally occurring radioactive materials (NORM) in solid waste or “drill cuttings” produced from unconventional drilling for natural gas extraction wells potentially pose environmental contamination risks; however, the composition and mobility of NORM in these solid wastes are poorly understood. In this study, the composition of NORM, including uranium, thorium, radium, lead, and polonium isotopes, was evaluated in three samples of drill cuttings extracted from a well drilled into the Marcellus Shale formation. Leachability of NORM in drill cuttings was characterized by leaching the solid waste with dilute acetic acid at four different pH values. The uranium-series radionuclides in cuttings and leachate samples displayed isotopic disequilibrium, suggesting some environmental mobility of radionuclides in these shale formations. Our results indicate that isotopic analysis of uranium-series radionuclides is needed for a more complete understanding of the potential environmental contamination risks associate...

Analytical Modeling to Simulate Gas Production for Various Tested Landfill Cells

AbstractThe gas extraction wells installed in landfills are used to control gas emission. The degradation of municipal solid waste (MSW) is the main influencing factor for gas production and migration. The symmetric equation of gas migration was established considering the gas extraction wells and peak behavior of the degradation rate. An analytical solution is presented. The peak behavior of degradation rate can be modeled by an equation. The steady degradation ratio of MSW is related to methane generation potential Lo in the LandGEM model. The extraction and injection tests can be well simulated by the symmetric change theory of gas pressure in landfills. From back analysis of the Brogborough test, both the MSW landfill degradation rate and the peak value of gas pressure increased with sludge addition. The degradation time at peak is less than about 700 days. The peak gas pressure in landfill with added sludge increases by 20%.

Elevated levels of diesel range organic compounds in groundwater near Marcellus gas operations are derived from surface activities

Hundreds of organic chemicals are used during natural gas extraction via high-volume hydraulic fracturing (HVHF). However, it is unclear whether these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and affect local water quality, either from those deep HVHF injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency's maximum contaminant levels, and low levels of both gasoline range (0-8 ppb) and diesel range organic compounds (DRO; 0-157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl) phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with (i) inorganic chemical fingerprinting of deep saline groundwater, (ii) characteristic noble gas isotopes, and (iii) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation.

埋立終了後の廃棄物最終処分場に設置された受動型ガス抜き管内の 温度・埋立ガス成分調査（第４報）

埋立終了後の廃棄物最終処分場に設置された受動型ガス抜き管内の 温度・埋立ガス成分調査（第４報）

Odor compounds from different sources of landfill: Characterization and source identification

This study investigated the odor compounds from different areas in a landfill site, which included the municipal solid waste (MSW)-related area, the leachate-related area and the sludge-related area. Nine sampling points were placed and 35 types of odorous substances were measured and quantified from these grabbed samples. The results showed that the main odorous substances emitted from landfill site were styrene, toluene, xylene, acetone, methanol, n-butanone, n-butylaldehyde, acetic acid, dimethyl sulfide, dimethyl disulfide and ammonia. In the MSW-related area, the highest concentrations of oxygenated compounds were observed at the gas extraction wells (GW), while sulfur compounds were rare. Ammonia in the sludge-related area was very abundant. Sludge discharge area (SD1) and sludge disposal work place (SD2) were representative points of pre- and post-drying, in which the characterizations of the emitted odorous gas were different. After chemical drying, the concentration of ammonia increased, whereas those of volatile fatty acids and sulfur compounds decreased. In the leachate-related area, relatively low concentrations of all those odorants were detected in leachate storage pool (LS), which may be due to the enclosure operation of the leachate storage pool. Using principal components analysis and cluster analysis, GW, SD1 and SD2 were distinguished from the other sampling points. The typical odorants in GW were acetaldehyde, ethyl benzene, xylene, methylamine and dimethyl formamide. The typical odorants in SD1 were methyl mercaptan, valeric acid and isovaleric acid, while those in SD2 were carbon disulfide, acetone, 3-pentanone, methanol and trimethylamine. The typical odorants in other sampling points were hydrogen sulfide, n-butylaldehyde and acetic acid.

Optimasi Sudut Ujung Pipa Penangkapan Gas Metana Pada Metode Arrow System

Drilling system on a pile of waste to get the methane gas is very difficult because the majority of waste that is made from plastic so it can get caught in the drill. Manual excavationis not allowed because it is very dangerous, while digging with heavy equipment has not been able to do because it requires a special tool that is able to push and pull waste surface. Makingholes with arrow system method that is larger arrowhead from the arrow shaft, is one alternative that can be tried to get a hole / gas extraction wells at the Landfill Supit Urang - Malang.Results hole larger than the arrow shaft is then filled with gravels as well extration methane in the landfill. The force required pile (arrow system) to the pole with pole diameter 26.7 cm and a maximum depth of 5.20 m (at point 1, the arrows point of 30˚ and 45˚) is a row of 63,087 kg and 79,717 kg . Optimum angle in terms of penetration force needs is the pole with arrowhead angle 30˚.