Chemical Composition Of Formation Waters Research Articles

Formation Waters Delineate Diverse Hydrogeologic Conditions at a Plate Scale: Eastern Flank of the Juan de Fuca Ridge

AbstractThe chemical composition of formation waters within the upper basaltic crust were calculated or measured at 24 sites on the northwest portion of the Juan de Fuca (JDF) Plate using data from sediment pore waters, scientific boreholes, and seafloor springs. Formation waters differ in composition across this ridge‐flank region because of variations in water‐rock reactions and residence times, exchange rates with overlying sediment pore waters, and microbial processes along flow paths. We interpret spatial variations in the solute composition of formation waters to resolve areas that are geochemically distinct or similar, lateral trends that result from water transport, areas where water‐rock reactions in the deeper crust are apparent, and sites of seawater recharge and formation water discharge. We provide evidence for large‐scale lateral flow associated with two (mostly) buried basement ridges on ∼1.4 and ∼3.5 Ma seafloor, which are subparallel to the JDF spreading axis to the west. Between these two ridges, where the seafloor and the sediment‐basement interface are relatively flat, formation waters have undergone extensive exchange with overlying sediment pore waters, consistent with a long residence time. Basaltic outcrops provide sites of seawater recharge and hydrothermal discharge, sometimes through the same feature, highlighting the heterogeneous nature of hydrogeologic conditions and processes. This work provides a blueprint for future plate‐scale studies to assess, for example, geologic controls of crustal age, spreading rate, and sedimentation on subsurface hydrologic patterns.

Environmental Impacts of chemical composition Produced Water (оn the Siyazan field example)

This article describes the increased environmental impact of fuel energy complex depending on growth in oil and gas production. At the moment, due to the intensification of oil and gas production, associated mineralized reservoir water is one of the main sources for environmental pollution, and sufficiently plays role at soil cover degradation. This paper reviews recent research analysis of the physical chemical composition of formation water and the effect of this composition on soil ecosystems on the example of monocline of Siyazan field. Water samples have been taken from of monocline of Siyazan field. This information has been used to determine the most significant contaminants and their geochemical behaviour. Based on the analysis results, the examined formation water samples were characterized in terms of various classifications used in oil and gas hydrogeology. And, conclusions were drawn and it was noted that the hydrochemical composition of mineralized reservoir waters to degradation of biocenoses and soil cover.

Mapping of potential environmental risks associated to formation water in the Oriente Basin, Ecuador

Formation water is the water produced jointly with oil as part of oil production process, which in Ecuador it is performed mainly within the Amazon region. Despite this region is highly vulnerable, due to its biodiversity and hydrological richness, formation water is produced in large volumes, contains toxic substances and receives limited treatment. This research determined the spatial distribution of the potential environmental risks associated to formation water chemical composition using geographic information systems to generate risk and vulnerability maps. Specifically, the objectives were 1) to analyze the chemical composition of formation water; 2) to compare formation water chemical composition between oil fields; 3) to determine the level of vulnerability of the environment and nearby populations; 4) to map the potential environmental risks associated to formation water; and 5) to review the current water treatment methods. Results show that formation water contains elements that are carcinogenic and with high bioaccumulation potential, like cadmium. Moreover, their concentration varies depending on the reservoir from where the water is extracted and the geographical location of the field. The potential risk of an area is determined by its well density, formation water quality and production volume, and the course of any nearby river. Therefore, Blocks 15 and 57 and the basin of the Aguarico River are associated to high environmental risk. Finally, water treatment process removes suspended solids and oil, while production chemicals slightly contribute to its toxicity. To track environmental potential risks, it is suggested periodical water quality evaluations of nearby rivers, similar environmental studies, and better land use planning by the local governments considering the potential risks associated to oil production activities.

Геохимическая роль метеорных вод как фактор формирования пустотного пространства коллекторов нефти и газа

The features of the chemical composition of formation waters of the Upper Permian, Lower and Middle Triassic aquifers within individual structures of the Malozemelsk-Kolguev monocline of the Timan-Pechora oil and gas bearing basin are examined. It is shown that the aquifers that, despite their remoteness from the recharge areas, had experienced repeated processes of dipping and uplifting of the territory, preserved the infiltration waters, but significantly transformed ones. To identify their genetic profile and determine the relationship with the processes of catagenetic changes, hydrochemical coefficients and indices of water saturation of calcium carbonate and calcium sulfate are calculated. It is established that the examined infiltration waters are characterized by high aggressiveness, dissolution ability, leaching and removal of main minerals. It is pointed out that the consequence of these processes is the formation of secondary void space and the creation of high capacitive and filtration properties of rocks. The universality of geochemical interaction between water and rocks in thermodynamically open geological systems is emphasized and it is confirmed by individual geological examples that the heterogeneity of the hydrochemical field can act as a cause of screening zones of oil and gas accumulation, as well as provide appropriate conditions for localization of hydrocarbon fluids.

Analysis of the application for the magnetohydrodynamic effect in the hydrocarbon production

Nowadays the main share of oil fields is at a late stage of operation. It is characterized by high water cut of the extracted products. Salts in the formation fluid, under certain thermobaric conditions, settle on the process equipment and they cause its failure. Failure of technological equipment entails the well’s downtime and high material costs. Water-soluble salts in the formation fluid are subject to electrolysis. There, the molecules of the substance are decomposed into ions. The Lorentz force acts when a magnetic field is applied to the ions. The magnetohydrodynamic effect is manifested in the formation fluid. The purpose of the article is to analyze the applicability of the magnetohydrodynamic effect for hydrocarbon production. The chemical composition of formation waters for some deposits is given. On its basis the chemical model for electrolysis of the main salts in sodium chloride and potassium chloride contained in the formation liquid is constructed. The design and operation principle of the simplest magnetohydrodynamic pump is considered. The description of the developed laboratory sample of the magnetohydrodynamic pump is given. The main conclusions are reflected in this article.

Characterising brines in deep Mesozoic sandstone reservoirs, Denmark

The Danish subsurface contains several sandstone units, which represent a large geothermal resource (Vosgerau et al. 2016). Currently, only three geothermal plants are operating in Denmark, but several exploration licences are expected to be awarded in 2019. Geothermal energy is exploited from deeply buried porous sandstones by bringing warm form­ation water (brine) to the surface, extracting the heat and returning the cooled water to the same sandstones. The reduced temperature of the brine during this process implies a risk of scaling, which may reduce reservoir permeability and hence injectivity. Predicting the chemical composition of formation waters, however, could help to reduce the risk associated with scaling in planned geothermal facilities.
 Here, we present a regional overview of the geochem­istry of brines from deep Mesozoic sandstones in the Danish Basin and North German Basin that supplements previous studies, notably by Laier (2002, 2008). The brine composition at shallow burial typically reflects the original (connate) formation water chemistry, which is determined by the original depositional environment of the sandstone, for example fluvial or marine. However, the mineralogical composition of the sandstone changes during burial, whereby some minerals may dissolve or precipitate when exposed to higher temperatures. These mineral changes are reflected in the brine composition, which typically becomes more saline with increased burial (e.g. Laier 2008; Kharaka & Hanor 2003). 
 The brine chemistry reported here shows a distinct depth trend, which reflects original connate formation waters that are modified through burial diagenesis. We have classified the brines into brine types, which are shown to be related to their depositional environment, depth, geological formation and geographical domains.

Occurrence and Origin of H2S from Volcanic Reservoirs in Niudong Area of the Santanghu Basin, NW China

A series of samples including natural gas, formation water, and rocks were collected from volcanic rock reservoirs in the Niudong area of the Santanghu Oilfields and analyzed for their mineral and/or chemical compositions and sulfur and carbon isotopes in order to investigate the occurrence and origin of hydrogen sulfide (H2S). H2S was mostly dissolved in the formation water along with petroleum production in the study area. The δ34S values of on-well H2S samples varied in a range of 9.2‰ to 20.5‰, probably indicating thermochemical sulfate reduction (TSR) and/or thermal decomposition of organic sulfur-bearing compounds (TDS) as the genetic process for H2S. However, the chemical composition of formation waters from the Kalagang Formation (C2k) and their coefficient of desulfurization also revealed that TSR could be the main principle for H2S formation. Considering the regional geological background, especially the tectonic structures and thermal evolution features of the basin, it was concluded that H2S in the study area was dominantly produced by thermal genesis with TSR as a domain through interactions between hydrocarbons and aqueous sulfate dissolved from sulfate minerals.

Formation of hydrochemical indicators for reservoirs of oil deposits of the Surgut arch

The causes of the spatial variation of hydrochemical characteristics of groundwater of some oil deposits of the Surgut crest of Western Siberia. On the basis of statistical processing of the database, including several thousand analyzes of groundwater salinity distribution histograms, concentration of Ca2+ and HCO3 for the main productive horizons deposits. Substantiates theinfluence of deep inflow (hydrothermal) treatment on the formation of the chemical composition of formation water of oil fields, which is expressed in increasing the depth of the content of HCO3 ion.

Comparison of geochemical data obtained using four brine sampling methods at the SECARB Phase III Anthropogenic Test CO2 injection site, Citronelle Oil Field, Alabama

The chemical composition of formation water and associated gases from the lower Cretaceous Paluxy Formation was determined using four different sampling methods at a characterization well in the Citronelle Oil Field, Alabama, as part of the Southeast Regional Carbon Sequestration Partnership (SECARB) Phase III Anthropogenic Test, which is an integrated carbon capture and storage project. In this study, formation water and gas samples were obtained from well D-9-8 #2 at Citronelle using gas lift, electric submersible pump, U-tube, and a downhole vacuum sampler (VS) and subjected to both field and laboratory analyses. Field chemical analyses included electrical conductivity, dissolved sulfide concentration, alkalinity, and pH; laboratory analyses included major, minor and trace elements, dissolved carbon, volatile fatty acids, free and dissolved gas species. The formation water obtained from this well is a Na–Ca–Cl-type brine with a salinity of about 200,000mg/L total dissolved solids. Differences were evident between sampling methodologies, particularly in pH, Fe and alkalinity. There was little gas in samples, and gas composition results were strongly influenced by sampling methods. The results of the comparison demonstrate the difficulty and importance of preserving volatile analytes in samples, with the VS and U-tube system performing most favorably in this aspect.

Effect of the Chemical Composition of Formation Water on gas Well Productivity

We have used logging data and the gas-to-water ratio to determine the water type in a specific zone for the Zizhou (China) gas field. The chemical analysis results for the water established that Na+, K+, and Ca2+ ions predominate. We studied the effect of water saturation on gas well productivity.

The role of vertical migration of high-temperature fluids in the genesis of formation waters in oil-gas fields in the north of the Western Siberian basin

All northern areas of Western Siberia exhibit a discontinuity in the normal vertical hydrochemical zoning and formation of an inversion hydrochemcial profile characterized by total mineralization of formation waters that decrease with depth and by the discovery of waters with mineralization levels of 1–7 g/L and less, as well as a simultaneous “inconsistent” change in the chemical composition of formation waters with Cl-Na-Ca to HCO3-Cl-Na deeper than 2–3 km and simultaneous “irregular’ change in the chemical composition of formation waters with Cl-Na-Ca to HCO3-Cl-Na. Based on the use of the B/Br ratio and a Na-K geothermometer, a conclusion is made that the formation of slightly ( 150°C) fluids saturated with CO2 into water-bearing rocks. This indicates the formation of deposits of hydrocarbons that are found in the regions of inversion waters as result of the upward vertical, but not lateral formation migration of a water-oil mixture.

Origin, chemistry and flow of formation waters in the Mississippian–Jurassic sedimentary succession in the west-central part of the Alberta Basin, Canada

The flow and chemistry of formation waters was analyzed in the Mississippian–Jurassic succession in the west-central part of the Alberta Basin, using publicly available standard chemical analyses of formation waters and drillstem test data collected by the petroleum industry in Alberta. The interpretation of the thoroughly culled hydrogeological data show that a transition between a southern and a northern basin-scale flow system takes place in the study area. In the southeastern half of the study area, the Mississippian–Jurassic hydrostratigraphic group represents a single continuous carbonate–sandstone aquifer system, consisting of the Lower Jurassic Nordegg Member, the Triassic Montney Formation, the Permian Belloy Formation and the Mississippian Stoddart and Rundle groups. The confining units are the competent Fernie and Exshaw–Banff aquitards at the top and base, respectively. The salinity of formation waters increases northwestwards from ∼50 to ∼150g/l, while the bicarbonate content decreases in similar fashion from >3 to ∼0.5g/l. The flow pattern, based on hydraulic heads, and chemical composition of formation waters indicate decreasing mixing of meteoric water, carried northward in the southern basin-scale long-range system, with heavier connate water present in the northern part of the study area. In the center and in the northeast, the Permian and Mississippian carbonates, and the Triassic Montney and Charlie Lake–Halfway sandstones form individual aquifers separated by the intervening Doig–Montney aquitard. The flow in the Charlie Lake–Halfway and the Permo-Mississippian aquifers is directed east–northeastward from the deformation front into the overlying aquitards, or discharging into the southern basin-scale flow system, respectively. Only in the Montney aquifer, the flow is directed inward, south–southwestward, drawn into a local hydrocarbon-saturated sink, which is created by a higher rate of gas escape than of gas generation through a low-permeability and capillary-seal region. The high salinity, in the 130–150g/l range, and low bicarbonate content (∼0.5g/l) of formation waters in the northern part of the study area indicate a connate origin. The relation of Na–Ca–Cl–Br concentrations in the formation waters suggest that these waters initially originated as seawater that was altered to some degree by subaerial evaporation and dolomitization, but halite dissolution probably is the main source of salinity. The driving mechanism for the flow of these waters could be either tectonic expulsion from deep strata in the deformed part of the basin, as suggested by the high salinity of these waters, or topography-driven meteoric recharge in the Rocky Mountains through a tortuous path, unidentified as yet. The integrated interpretation of flow and chemistry of formation water shows that Mississippian–Jurassic formation waters in the deep, west-central parts of the Alberta Basin have been influenced less by mixing with meteoric water than was identified previously in the central, southern and northern parts of the basin. The main reasons for the isolation of ‘relict’ Mississippian–Jurassic formation waters in the deep Alberta Basin are effective confining aquitards and the fact that this area is influenced only marginally by mixing with meteoric water carried by a gravity-driven flow system.

FORMATION WATERS, HOT SPRINGS AND MINERALIZATION PHENOMENA ALONG THE EASTERN SHORE OF THE GULF OF SUEZ

Abstract The chemical composition of formation waters tapped in oil wells and emerging as hot springs along the Suez coast of Sinai was examined. A scheme is proposed for the geochemical evolution of these waters and their relation to the geological history of the area. The thermal regime in the investigated area is characterized by high gradient foci located in the immediate proximity of major faults. Fe—mineralization, dolomitization and concentrations of heavy metals were observed on the eastern shore of the Gulf of Suez. The Suez formation waters have equivalent ionic ratios similar to those of the hot brines found in the three Deeps of the Red Sea (Degens and Ross, 1969). The thermal and mineralization phenomena also show a resemblance to those of the Deeps.

Geological Considerations on the Characteristics of Natural Gas found in Hirakida, Shiunji and Higashi-Niigata Gas Fields

Characteristics of natural gas found in several Japanese fields are controlled mainly by geologic factors; particulary it was shown that the methanc contents and specific gravities of gas from the definite geologic horizons are almost similar respectively. Effects of pressure and temperature on the composition of natural gas seem to be insignificant. Chemical composition of formation water and foraminiferal distributions are closely related to the sedimentary environments of each formation. The writer supposes that the primary migration and accumulation of natural gas out of its source sediments have occured at a relatively early stage of compaction after the deposition of the sediments.