High-temperature Formation Research Articles

The research of new type gel plugging agent for deep well

ABSTRACT A gel plugging agent was developed to solve the problem of high-temperature and high-salinity formation of leakage in deep wells. The plugging agent was composed of Tianqing glue, Titanate, Carboxymethyl cellulose (CMC), high-temperature stabilizer(A) and solid-phase particles. According to the deep well plugging material requirements, the effects of pH, temperature, salinity and flow state on gel gelling time and viscosity were studied. Then the plugging agent was evaluated in terms of the pumpability, pollution resistance and compatibility with solid particles, and sealing experiments were carried out by sand beds with 10 ~ 20 mesh and 20 ~ 40 mesh respectively. It showed that the resistance to high temperature can reach 120 °C at the field of 0.5% Tianqing glue, 0.25% Titanate, 0.4% CMC, 0.4% A. Na+ and Ca2+ have hydrolysis effect on the gel, however, oil did not affect the crosslinking of polymer, and water, drilling fluid and cement slurry had a little effect on the viscosity. The gel consistency of 28BC shows a good pumpability. When adding 5% of solid particles, the maximum bearing pressure was 5MPa.

Petrogenesis of the early Permian A-type granites in the Halajun region, southwest Tianshan, western Xinjiang, NW China: implications for geodynamics of Tarim large igneous province

ABSTRACT Formation of a large igneous province, an explosive magmatic event in earth, is intimately related to geodynamic processes. The Tarim large igneous province, a famous representative in China, contains A-type granites. However, the petrogenesis of the A-type granites is debated. Some researchers think that the A-type granites are developed through extensive fractionation of magma derived from partial melting of newly underplated or gabbroic rocks. Others insist that the A-type granites are developed through intensive fractional crystallization of plume-derived mafic magma. Here, we present zircon U–Pb ages and whole-rock geochemical and Sr–Nd isotopic data for the Kezilekezitage, Keziertuo, Tamu, and Halajun II intrusions in northwest Tarim to elucidate their petrogenesis and geodynamic implications. Zircon U–Pb dating yielded crystallization ages of the Kezilekezitage, Keziertuo, and Halajun II intrusions of 275.1 ± 3.1 Ma (MSWD = 1.14), 274.8 ± 1.8 (MSWD = 0.46) and 275.6 ± 0.7 (MSWD = 1.04), respectively. The whole-rock geochemistry of the four intrusions is characterized by REE and HFSE enrichment, Ba, Sr, P, Ti, and Eu depletion, εNd (t) values of – 1.2 to +0.3, two-stage Nd model ages (T2DM) of 1.14–1.02 Ga, and an A1-type granite affinity. Whole-rock zircon geothermometry indicates a high formation temperature of 721–924°C. It is concluded that these A-type granites were generated by partial melting of Neoproterozoic OIB-like rocks, coupled with extensive fractional crystallization and minor crustal contamination. The production of the A-type granites at ca. 275 Ma represented the termination and greatest degree of lithospheric thinning during large igneous province formation.

Thermal convection dolomitization induced by the Emeishan Large Igneous Province

Abstract The mechanism of dolomitization has long been debated due to complex sedimentary and diagenetic conditions. Large-scale dolomite bodies were recently discovered in the Permian Cisuralian Qixia Formation (284–273 Ma) in the northwestern Sichuan Basin, providing an opportunity to understand the dolomitization associated with the Emeishan Large Igneous Province (ELIP). Traditionally, the dolomites in the Sichuan Basin have been interpreted as hydrothermal dolomitization because of the hydrothermal impacts from the ELIP. Here, we report new petrographic and geochemical data on the Permian dolomites, which we grouped into two categories (matrix dolomites or Md1–Md3 and cement dolomites or Cd), that support thermal convection dolomitization. The petrographic and geochemical features (δ13C, δ18O, REE, Mn/Sr ratios, 87Sr/86Sr ratios) suggest that Md1 were formed in penecontemporaneous seawater, whereas Md2, Md3, and Cd were formed in fluids resembling Permian seawater during shallow burial stage, of which both dolomitizing fluids are non-hydrothermal. High formation temperature inferred from fluid inclusion is consistent with the low δ18O values of the Md2, Md3 and Cd, suggesting that the ELIP event may have provided the heat for the dolomitization in the Qixia carbonate platform. The formation of the widespread dolomite bodies was facilitated by the rapid convection exchange between warm pore seawater in the Qixia strata of the platform margin and cold water from outside the slope. Therefore, we demonstrate that the dolomites in the northwestern Sichuan Basin are mainly due to thermal convection dolomitization in the shallow burial stage. This study provides important implications for the mechanism of dolomite formation linked to abnormal geothermal activity.

Testing of preformed particles polymer gel technology on core filtration models to limit water inflows

In order to reduce watering of wells and equalize their injectivity profiles, the prospects of introducing PPG technology in Russian fields are considered, in which preformed particles polymer gel are pumped into the injection well. These particles, being a supersorbent based on polyacrylamide, absorb water, become elastic, which allows them to shrink and tear in narrow filtration channels. When the polymer is filtered along permeable layers saturated with water, polymer particles accumulate in waterlogged intervals and thus they form a polymer plug, which redistributes the filtration flows and increases the coverage of the formation by the process of oil displacement.More than 4000 downhole operations have been carried out in the fields of China and the USA using PPG technology by now. In domestic fields in Western Siberia, there is limited experience in applying a similar technology in high-temperature formations with low mineralization of formation water. Due to the absence of hydrolytic processes in polyacrylamide, well-known domestic compositions are not applicable due to the low absorption capacity in the conditions of low-temperature deposits with increased mineralization of formation water.The authors synthesized a polymer based on polyacrylamide by block polymerization, which allows to obtain a high absorption capacity, including for low-temperature formations with high mineralization of formation water, which is typical for Perm Territory fields.Filtration experiments were carried out on core models with the composition developed by the authors, this composition focused on low formation temperatures and high mineralization of formation water. As a result of the experiments, it was found that the swollen particles of the gel are able to pass into fractures with a diameter less than their own size at least 20 times. With a significant increase in the viscosity of the dispersion medium, the stability of the suspension increases. Particles of polymer gel have the necessary strength for injection in the field conditions. The fracture permeability during polymer injection decreases by several times and becomes comparable with the permeability of pore collectors.

Continuous Flow Conditions for High Temperature Formation of a Benzodioxan Pharmaceutical Intermediate: Rapid Scaleup for Early Phase Material Delivery

We have developed a continuous flow method to enable rapid scaleup of an enantioenriched benzodioxan intermediate. We propose that the reaction proceeds through an intramolecular SNAr cyclization. ...

Transient Thermo-Poroelastoplasticity Finite Element Analysis of Inclined Wellbore Stability

Wellbore instability is a crucial concern problem in highly inclined well drilling, extended reach well drilling and horizontal well drilling, particularly in high temperature and high pressure (HPHT) formations. However, few studies have concentrated on the three-dimensional inclined wellbore instability analysis considering the influence of thermo-poroelastoplasticity and filter cake. In the present study, a three-dimensional inclined wellbore stability model fully coupling thermo-poroelastoplasticity and considering filter cake is created and analyzed using finite element analysis. This model can be used for the wells with any deviation angle and azimuth angles simply by changing the far field stresses and boundary conditions. The distribution of pore pressure and wellbore stress under various deviation angles, consolidation time and temperature gradients are investigated. The research results show that, the wellbore instability problem is generally severe in the inclined wells comparing to the vertical wells. The wellbore becomes unstable as the consolidation time increases, and it is more unstable under positive temperature gradient than under negative; the filter cake can reduce the pore pressure and stress around the wellbore, it prevents the wellbore from shear failure in vertical well (deviation 0o), and prevents the wellbore from tensile failure in inclined well especially in the horizontal well (deviation 90o). The results obtained in this paper can benefit a deeper understanding of the instability mechanism of inclined wellbore.

Mathematical modeling heat and mass transfer in a vertical hydraulic fracture crack during inflation and cleaning*

When designing hydraulic fracturing for high-temperature formations, it is important to know the temperature change in the fracture during the injection of fracturing fluid. The temperature profile in the hydraulic fracture is necessary to calculate the optimal composition of the fracturing fluid, which necessarily includes a crosslinker (crosslinker) and a breaker (breaker), the concentration of which is calculated by the temperature at the end of the crack. Currently, this concentration is calculated based on the maximum temperature of the formation, which can lead to a decrease in the efficiency of hydraulic fracturing, since a breaker will not completely destroy the crosslinked gel. Therefore, when a well is brought into operation after the stimulation, proppant removal may occur, reducing the effectiveness of stimulation to zero. In this regard, the optimization of the decision-making process in the design of hydraulic fracturing in terrigenous and carbonate reservoirs by calculating the optimal parameters of process fluids based on predicting heat and mass transfer processes occurring during processing is a very urgent task. A tool has been developed to improve the design efficiency of hydraulic fracturing based on mathematical modeling of temperature fields in a hydraulic fracture during its development and during the period of technological sludge. A mathematical model that describes the temperature dynamics in a hydraulic fracture taking into account fluid leakage into the formation represents the evolutionary equation of convective heat transfer with a source, which is defined as the density of the heat flux from the formation. To check the adequacy of the model of temperature dynamics in a hydraulic fracture, a model of temperature recovery in a fracture is presented with the subsequent adaptation of simulation results to actual data. Developed mathematical models can be used in hydraulic fracturing simulators.

Application of Thermal Resistant Gemini Surfactants in Highly Thixotropic Water-in-oil Drilling Fluid System

AbstractTraditional water-in-oil drilling fluids are limited by their shear thinning behavior. In this article, we propose the synthesis of a thermal resistant quaternary ammonium salt gemini surfactant DQGE-I. This surfactant was synthesized using monomers such as N,N-dimethyl-1,3-propanediamine, organic acids and epichlorohydrin, as well as blocking groups such as N-vinylpyrrolidone (NVP). The prepared surfactant exhibited various advantages over traditional surfactants, including excellent thermal stability, good emulsifying and wetting capability. The use of these surfactants was shown to improve the compactness of emulsifier molecules at the oil/water interface, as well as the overall emulsificaiton effect. Laboratory studies revealed that water-in-oil emulsions prepared using DQGE-I showed high emulsion breaking voltage, low liquid precipitation and small and uniformly distributed emulsion drops. Highly thixotropic water-in-oil drilling fluids based on DQGE-I showed low viscosity, high shear rate and thermal tolerance up to 260oC. Additionally, the proposed fluid was applied in 16 wells (including WS1-H2, GS3 and XS1-H8) in the Daqing Oilfield. Testing showed that DQGE-1 exhibited excellent rheological behavior and wall-building capability. The emulsion breaking voltage exceeded 1500 V, and the yield point/ plastic viscosity ratio exceeded 0.4. The use of this surfactant can help to solve problems such as high formation temperature and poor well wall stability.

High corrosion resistance film on rebar by cerium modification

A cerium film was prepared on the surface of rebar by chemical conversion method to enhance its corrosion resistance. The film in the simulated concrete pore solution was measured by electrochemical method, transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The effect of temperature on film formation was studied, and the optimum temperature was determined at 35 °C. The film produced by too high formation temperature has more defects, resulting in the lower corrosion resistance. The Ce film resistance increased with time evolution until 800 h, then decreased and stabilized. The Ce film layer has a double-layer film structure, the upper layer is an oxide of cerium, and the underlayer is an oxide of iron. Results revealed that after being immersed in the simulated concrete pore solution, the corrosion resistance of the Ce film was enhanced by self-densification.

Evolution patterns of coal micro-structure in environments with different temperatures and oxygen conditions

Before mining, a deep coal seam exists in a state with a high formation temperature and high stress. After mining, the coal body is exposed to oxygen, and the oxidation reaction results in significant changes in the micro-structure of the oxidized coal body. To understand the change process, in this paper, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy are employed to test a coal body subjected to flow of hot gas. The evolution patterns of the coal oxidation micro-structure under different temperatures and oxygen conditions are compared and analysed. The results show that in an environment with oxygen, as the temperature increases, the stacking height (Lc) of the coal macromolecular lattice follows an overall increasing trend and has a self-repair capability. During oxidation, the spatial arrangement of the evolution of the coal molecular structure is reversible. In an environment without oxygen, the hydroxyl (–OH) peak height and peak area exceed those of an environment with oxygen, which suggests that the –OH group facilitates coal oxidation. Coal functional groups under high-temperature fracture polymerize constantly, and oxidation produces new functional groups.

Experimental study of injection strategy for Low-Tension-Gas flooding in low permeability, high salinity carbonate reservoirs

Previous experimental studies have proven that Low-Tension-Gas (LTG) flooding can be a suitable enhanced oil recovery (EOR) method for low-permeability carbonate reservoirs with high salinity and hard formation brine. LTG flooding was observed to improve oil recovery by combining two effects: a reduction of the interfacial tension (IFT) between oil and water and mobility control through the formation of in-situ foam with an injected gas. However, the high cost of chemicals and/or the limited supply of gas could make this process economically challenging.In this study, the primary goal was to reduce the amount of injected gas and surfactant to make the LTG process more economically feasible. A low-permeable (<10 mD) limestone reservoir with a high formation brine salinity (>200,000 ppm and hardness 19,000 ppm) and temperature 69 °C was the target reservoir of this study. Effect of varying the concentration and pore volumes of the ultra-low IFT inducing surfactant slug injected on oil recovery was studied. Nitrogen gas was co-injected during selected time periods throughout the entire surfactant injection in order to identify the significance of mobility control during the crucial phases of the LTG flooding. The coreflood results emphasized the significance of the injection of gas, even at lower foam quality, for the maintenance of mobility control. Ultimate oil recovery of over 60% (residual oil post waterflood) was achieved, even after reducing the surfactant concentration by 75% and inducing a different in-situ salinity profile as compared to earlier studies. An innovative method for measuring surfactant adsorption using Liquid Chromatography and Mass Spectrometry (LC-MS) was developed, which could provide individual surfactant transport data for each of the three classes of surfactants used.

Synthesis and Performance Evaluation of Temperature-controlled Viscous Acid

A temperature-controlled viscous acid thickener was obtained by copolymerizing acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, diallyl dimethyl ammonium chloride, and N-vinyl-2-pyrrolidinone, four monomers by aqueous solution polymerization, the mass ratio of the four monomers was 6: 2: 1: 1, the reaction temperature was 45°C and the reaction time was 6 h. The total mass concentration of the monomer was 25% and the oxidation-reduction system of ammonium persulphate and sodium hydrogen sulfite (mass ratio 1: 1) was used as the initiator, the amount was 0.9% of the total mass of the monomer, and the pH of the reaction solution was 6–8. Selecting glutaric dialdehyde and zirconium(IV) acetylacetonate as cross-linking agents, and compounding the synthesized quaternary copolymer after the mass ratio of the two reagents was 1: 1 to achieve acid temperature control viscous properties, were carried out. At 90°C, the quadripolymer and the cross-linking agent were mixed at a mass ratio of 5: 3, and then cross-linked at 60, 80, and 90°C, respectively, as time increased. The apparent viscosity increased sharply, and the apparent viscosity reached a maximum after 20, 15, and 10 min, and the maximum values were 680, 690, and 750 mPa s, respectively. The reaction of marble with thickening acid (20% hydrochloric acid + 1% thickener) and temperature-controlled viscous acid (20% hydrochloric acid + 1% thickener + 0.6 cross-linking agent) was performed at 90°C. The mass loss of marble was 58 and 42% of that of 20% pure hydrochloric acid, respectively. The performance evaluation results show that the temperature-controlled viscous acid has a good compatibility, and the retarding performance is greatly improved compared with the conventional thickened acid. It has good cross-linking and gel breaking performance under high temperature conditions and is suitable for high temperature formations with temperatures above 90°C. Between its excellent compatibility, it can be selected according to the corresponding formation conditions and construction purposes, and other types of acid working fluid or oilfield additives can be used together to achieve better construction results.

Precipitates of α-cristobalite and silicate glass in UHP clinopyroxene from a Bohemian Massif eclogite

AbstractLow-pressure metastable nanoscale crystals of α-cristobalite have been observed epitaxially ex-solved in cores of UHP clinopyroxene from the Bohemian Massif, Czech Republic. SAED patterns and HRTEM images detail the close structural relationship between host clinopyroxene and α-cristobalite precipitate: [001]Di||[010]α, (010)Di ~||(101)α. TEM results indicate that α-cristobalite exsolved from host clinopyroxene. Non-crystalline Al-bearing silicate phases, also exsolved from UHP clinopyroxene, possesses Al/Si ratios close to eutectic compositions in the system NaAlSi3O8-SiO2-H2O system. The presence of glass exsolution suggests a high-temperature formation environment and presence of water. The α-cristobalite formed in a localized low-pressure, micro-environment formed through exsolution of vacancies and excess silica from the host pyroxene lattice. This micro-environment may be a result of negative density changes due to excess lower density silica exsolving from higher density pyroxene during an exsolution process that involved no localized volume change. Interface-controlled exsolution via lattice matching at the diopside/cristobalite interface, and stability changes and melting point depression due to nanoscale size effects contributed to the formation and persistence of this metastable phase. Amphibole in association with α-cristobalite and some non-crystalline silicate phases may be a clue to localized water quantities; silica exsolution with amphibole may have formed below the eutectic temperature and at a later stage than non-crystalline silicate phases without amphibole. Silica rods in Nové Dvory clinopyroxenes were previously thought to be quartz; however, our investigation reveals various low-pressure, high-temperature, and/or metastable phases greatly affected by the presence of vacancy and OH in clinopyroxenes. The results will help us better understand OH in the UHP pyroxene and even water release in the mantle.

Modeling the confined fluid flow in micro-nanoporous media under geological temperature and pressure

Understanding the fluid flow in confinement space is the important task for CO2 storage and unconventional gas production. The high temperature and pressure in geological formation proposed a challenge to the traditional model, which ignores the influence of temperature and pressure on the confined single-phase flow and two-phase flow. In our work, an analytical model is proposed to characterize the liquid flow and two phase flow in tight porous media with further considering the influence of temperature and pressure on fluid transport in confinement space. The results demonstrate that solid-liquid interactions will rise up the flow resistance of confined water and reduce the liquid permeability of tight porous media. Additionally, as the burial depth increases, the increasing temperature will not only increase the fluidity of bulk water but also weaken the effect of solid-liquid interactions, and the coupled effects can increase the water volume flux in geological formation. For two-phase flow in the formation, the high temperature and pressure result in small Knudsen number and low gas relative permeability branch while the high temperature increases the water fluidity and rises up the water relative permeability branch. The output of gas can increase Knudsen number, promoting the gas flow capacity and rising up the gas relative permeability branch.

Effect of BaO on mechanical and hydration characteristic of C8A6P as predominant mineral in phosphoaluminate cement

Phosphoaluminate cement clinker (PAC) was one type of cementitious material due to its high durability and mechanical performance. As the predominant mineral phase in PAC, the high-temperature formation and property of calcium phosphoaluminate mineral (C8A6P) were related closely with hydration and mechanical characteristic for PAC. Thus, the influence of BaO on the performance of C8A6P mineral phase was investigated carefully in this paper. It was found that BaO of 17.5–20% content could endow C8A6P mineral with predominant mechanical performance. This was due to the fact that C8A6P mineral was activated by BaO. Excessive BaO would lead to the formation of new unexpected phase BaO·Al2O3. The limited solid solubility of BaO in C8A6P mineral was 20%. The addition of BaO changed the ratio of hydration products of C2(A,P)H8 and C(A,P)H10 for C8A6P mineral.

Improved Alkali Intercalation of Carbonaceous Materials in Ammonia Solution

Alkali‐intercalated graphite compounds represent a compelling modification of carbon with significant application potential and various fundamentally important phases. The intercalation of graphite with alkali atoms (Li and K) using liquid ammonia solution as a mediating agent is reported. Alkali atoms dissolve well in liquid ammonia, which simplifies and speeds up the intercalation process, and it also avoids the high temperature formation of alkali carbides. Optical microscopy, Raman, and electron spin‐resonance spectroscopy attest that the prepared samples are highly and homogeneously intercalated to a level approaching stage‐I intercalation compounds. The method and the synthesis route may serve as a starting point for the various forms of alkali‐atom‐intercalated carbon compounds (including carbon nanotubes and graphene), which can be exploited in energy storage and further chemical modifications.

Thermoresponsive Bentonite for Water-Based Drilling Fluids.

As an important industrial material, bentonite has been widely applied in water-based drilling fluids to create mud cakes to protect boreholes. However, the common mud cake is porous, and it is difficult to reduce the filtration of a drilling fluid at high temperature. Therefore, this paper endowed bentonite with a thermo response via the insertion of N-isopropylacrylamide (NIPAM) monomers. The interaction between NIPAM monomers and bentonite was investigated via Fourier infrared spectroscopy (FTIR), isothermal adsorption, and X-ray diffraction (XRD) at various temperatures. The results demonstrate that chemical adsorption is involved in the adsorption process of NIPAM monomers on bentonite, and the adsorption of NIPAM monomers accords with the D–R model. With increasing temperature, more adsorption water was squeezed out of the composite when the temperature of the composite exceeded 70 °C. Based on the composite of NIPAM and bentonite, a mud cake was prepared using low-viscosity polyanionic cellulose (Lv-PAC) and initiator potassium peroxydisulfate (KPS). The change in the plugging of the mud cake was investigated via environmental scanning electron microscopy (ESEM), contact angle testing, filtration experiments, and linear expansion of the shale at various temperatures. In the plugging of the mud cake, a self-recovery behavior was observed with increasing temperature, and resistance was observed at 110 °C. The rheology of the drilling fluid was stable in the alterative temperature zone (70–110 °C). Based on the high resistance of the basic drilling fluid, a high-density drilling fluid (ρ = 2.0 g/cm3) was prepared with weighting materials with the objective of drilling high-temperature formations. By using a high-density drilling fluid, the hydration expansion of shale was reduced by half at 110 °C in comparison with common bentonite drilling fluid. In addition, the rheology of the high-density drilling fluid tended to be stable, and a self-recovery behavior was observed.

Pressure effects on the carbonation of MeO (Me = Co, Mn, Pb, Zn) for thermochemical energy storage

Metal carbonates are attractive materials for combining carbon capture and thermochemical energy storage. Carbonate materials feature high decomposition and formation temperatures and may be considered in applications in combination with concentrating solar power. In the present study in-situ P-XRD carbonation (1–8 bar CO2) and reactor-based experiments (1–55 bar CO2) are combined focusing on the effect of elevated CO2 pressures on carbonation of metal oxides. Carbonation of MnO and PbO at CO2 pressures between 8 and 50 bar in the presence of moisture resulted in reaction with CO2, forming the corresponding carbonates at notably lower temperatures than under dry CO2 atmosphere of 1 bar. This enables the application of metal oxide/metal carbonate reaction couples for energy storage at temperatures between 25 and 500 °C. Based on the reversible carbonation/decarbonation of PbO under varying CO2 pressures, an isothermal storage cycle between PbO/PbCO3·2PbO, triggered by changing the CO2 pressure between 2 and 8 bar, was developed.

Synergistic Effect of the Heterostructure of Au Nanoislands on TiO2 Nanowires for Efficient Ionization in Laser Desorption/Ionization Mass Spectrometry.

A combination nanostructured matrix with metal Au nanoislands and semiconductor TiO2 nanowires is presented to enhance both desorption and ionization efficiency in laser desorption/ionization (LDI) mass spectrometry. The heterostructure of Au nanoislands on TiO2 nanowires was fabricated via (1) TiO2 nanowire synthesis through a modified wet-corrosion method and (2) Au nanoisland formation through thermal annealing of a sputtered Au layer on the TiO2 nanowires. Herein, the synergistic effect of this heterostructure for highly efficient ion production was experimentally elucidated in terms of the formation of high temperature on the surface of Au and the creation of a Schottky barrier at the Au-TiO2 interface. Finally, four types of immunosuppressors were analyzed to demonstrate the improved ionization performance of the heterostructure for LDI mass spectrometry.

Rare-earth and trace elements and hydrogen and oxygen isotopic compositions of Cretaceous kaolinitic sediments from the Lower Benue Trough, Nigeria: provenance and paleoclimatic significance

This study evaluated the Cretaceous (Campanian–Maastrichtian) kaolinitic sediments of the Ajali/Mamu and Enugu/Nkporo Formations from the Lower Benue Trough of Nigeria. A combined method of inductively coupled plasma–mass spectrometry and isotope ratio mass spectrometry was used to investigate trace and rare-earth element geochemistry and hydrogen and oxygen isotopic compositions. These data were then used to infer the sediments’ provenance and paleoclimatic conditions during their deposition. The sediments contained low concentrations of most trace elements, with the exceptions of Zr (651–1352 ppm), Ba (56–157 ppm), V (38–90 ppm), and Sr (15.1–59.6 ppm). Average values of Co and Ni were 1.5 and 0.7 ppm, respectively. Trace and rare earth element values were lower than corresponding values for upper continental crust and Post-Archean Australian Shale, with the exception of Zr. The samples showed only slight light rare-earth enrichment and nearly flat heavy rare-earth depletion patterns, with negative Eu and Tm anomalies, typical of felsic sources. Geochemical parameters such as La/Sc, Th/Sc, and Th/Co ratios support that the kaolinitic sediments were derived from a felsic rock source, likely deposited in an oxic environment. 18O values ranged from + 15.4 to + 21.2‰ for the investigated samples, consistent with a residual material derived from chemical weathering of felsic rock and redeposited in a sedimentary basin (typical values of + 19 to + 21.2‰). While in the basin, the sediments experienced extended interactions with meteoric water enriched in δD and δ16O. However, the variation in δD and δ16O values for the investigated samples is attributed to the high temperature of formation (54–91 °C). The δD and δ18O values suggest that the sediments, although obtained from different localities within the Lower Benue Trough, formed under similar hot, tropical climatic conditions.