Swelling Inhibitor Research Articles

Investigation of ammonium–lauric salt as shale swelling inhibitor and a mechanism study

In this work, a series of ammonium–lauric salts (ALS) was prepared with lauric acid and amines as small molecular shale swelling inhibitor. The inhibitors were screened by the linear expansion test first, and the result shows that the inhibitor prepared by lauric acid and diethylenetriamine with the mole ratio of 2:1 (ALS-2) displays excellent inhibition effect on the hydration expansion of bentonite. The inhibition of ALS-2 to bentonite was fully evaluated by various methods in the following work, including clay linear swelling test and particle distribution measurement. The results show that ALS-2 has superior performance to inhibit the hydration swelling and dispersion of bentonite, and the swelling rate of bentonite in 0.5% ALS-2 was reduced to 29.7%. In water-based drilling fluid, ALS-2 is compatible with the conventional additives, and it can improve the lubricity of the mud cake obviously after aged under 120°C. Besides, it can control the particle size of bentonite in water. The inhibition mechanism of the ammonium–lauric salts was discussed in detail through physical adsorption, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy.

Damage phenomenon and petrophysical properties of sandstones at the Phnom Bakheng Temple (Angkor, Cambodia): first investigations and possible conservation measures

Sandstones, clay in the form of bricks and laterite are the building materials used by the Khmer to construct the imposing and magnificent temples in Southeast Asia. Many of these monuments suffer from fracturing, sanding, contour scaling, crust formation and salt weathering. The affinity to weathering is closely connected to the type of material. Two sandstone types classified as feldspathic arenite and quartz arenite of Angkor as well as two arkosic sandstones from Thailand are described and investigated in this study. Important petrophysical properties determined for the different sandstones consist of hydric expansion, thermal expansion, pore radii distribution and ultrasonic velocity. Different investigations such as capillary water uptake, surface hardness, hygroscopic water sorption, and salt resistance tests were undertaken in the laboratory to characterize the various rock types. Observations and quantified damage mapping were done onsite at the Phnom Bakheng Temple. Contour scaling in the form of weathering crusts is one of the main deterioration features observable at the Angkor monuments. Comparisons are made between the building stone, the crust material from the Phnom Bakheng Temple and fresh stone material used for restoration. Significant differences in hydric and especially in thermal expansion of the crust and sandstone have been determined. The results seem to indicate that extensional processes occur, which can be considered a force for detachment (i.e., contour scaling, flaking). In an experimental trial, the hydric and thermal expansion of the weathering crust and the building stone was significantly reduced by using a weak acid for the crust and a swelling inhibitor for the original building stone.

Investigation of Oleate-Diethylamine-Epichlorohydrin Copolymer as a Clay Swelling Inhibitor for Shale Oil/Gas Exploration

Oleate graft copolyammonium (OGCA) was prepared and its performance as a shale inhibitor was evaluated by bentonite linear expansion test, anti-swelling experiments, mud ball experiments in water-based drilling fluid. Anti-swelling results shows that anti-swelling rate of OGCA reaches up to 89.7% and OGCA has strong inhibitive capability to bentonite hydration swelling confirmed by the result of mud ball experiment. From the results it was found that both OGCA and modified starch have an excellent synergetic defiltration effect on the water-based drilling fluid. The good performance of OGCA as a shale inhibitor should be contributed to its good capacity of controlling the particle size of bentonite. The inhibition mechanism of the polyamine salt was analyzed by thermogravimetric analysis and scanning electron microscope.

A triterpenoid saponin as an environmental friendly and biodegradable clay swelling inhibitor

The drilling industry is motivated to develop high performance clay swelling inhibitors with good biodegradability and low toxicity. In this study, the non-ionic surfactant glycyrrhizin was obtained as Glycyrrhiza glabra root extract (GGRE) as a clay swelling inhibitor. The swelling inhibitive property of the biosurfactant was systematically evaluated through various experiments including mud making, filtration, shale cuttings recovery, sedimentation, scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA). We compare the performance of our surfactant with a synthetic surfactant (TX-100) and a commonly used clay inhibitor (KCl). Compared to the baseline swelling test without inhibitors, the aqueous solution of GGRE shows much more montmorillonite (Mt) loading capacity and fluid loss, less shale cuttings disintegration, unstable Mt dispersion, larger aggregated Mt particles, and lower Mt mass loss. The inhibitive performance of the GGRE was found to outperform that of the KCl. The results show that TX-100 does not provide inhibition. The compatibility with the drilling fluid formulation was investigated through the rheological and fluid loss analysis. GGRE is found to be compatible with the commercial drilling fluids additives. The inhibition mechanism was also investigated through wettability investigation and FT-IR analysis. The results show that GGRE can strongly reduce the hydrophilicity of Mt. From FT-IR spectra, the interaction between Mt and GGRE is obvious. Our results imply that GGRE possesses good inhibitive characteristic in hindering Mt swelling. The molecule of glycyrrhizin—the main component of GGRE—consists of a hydrophobic triterpenoid backbone, connected by glycosidic bonds to a hydrophilic group. The inhibition mechanism is hypothesized through the formation of a hydrophobic shell on Mt's surfaces; the hydrophilic group of the glycyrrhizin interacts with the oxygen atoms available on Mt's surfaces, while the hydrophobic part orients toward the aqueous phase. The results obtained from this research will be beneficial to enhanced oil recovery studies in Mt-rich formations.

Synthesis and evaluation of a novel monomeric amine as sodium montmorillonite swelling inhibitor

A novel monomeric amine sodium montmorillonite swelling inhibitor: N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide was obtained from diethanolamine, 1-bromotetradecane, and 1, 2-dibromoethane. N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide was characterized by means of Fourier transform infrared, 1H NMR spectroscopy, elemental analysis, linear swelling tests, particle size distribution tests, X-ray diffraction, and thermogravimetric. Linear swelling tests showed that the swelling height of sodium montmorillonite in 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution was only 2.0 mm after 16 h (fresh water was 5.0 mm). Particle size distribution tests exhibited that the median diameter and mean particle size of sodium montmorillonite in 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution obviously increased to 16.1 and 85.4 µm, respectively (fresh water was 8.1 and 21.8 µm). In thermogravimetric tests, in comparison with pure sodium montmorillonite, the decrease of water content in sodium montmorillonite/ N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide indicated N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide expelled the water molecules out of the interlayer, which was beneficial to wellbore stability. Fourier transform infrared spectra of certain concentration N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide/sodium montmorillonite indicated the successful physical adsorption and interaction between N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide with sodium montmorillonite. In addition, the results of X-ray diffraction tests showed the obtained 1.0 wt% N1, N2-ditetradecy- N1, N1, N2, N2-tetrakis (2-hydroxyethyl) ethane-1,2-diaminium bromide solution could remarkably reduce the interlayer distance of wet sodium montmorillonite (from 1.94 to 1.37 nm).

Investigation of melamine derived quaternary as ammonium salt potential shale inhibitor

Melamine, sodium chloroacetate and sodium hydroxide were used as raw materials to synthesize a kind of neutral quaternary ammonium salt (NQAS) as potential clay swelling inhibitor and water-based drilling fluid additive, and the reaction conditions were screened based on the linear expansion rate of bentonite. The inhibitive properties of NQASs were investigated by various methods, including montmorillonite (MMT) linear expansion test, mud ball immersing test, particle distribution measurement, thermogravimetric analysis and scanning electron microscopy etc. The results indicate that NQAS can inhibit expansion and dispersion of clay in water effectively. At the same condition, the bentonite linear expansion rate in NQAS-6 solution is much lower than those of others, and the hydration expansion degree of the mud ball in 0.5% NQAS-6 solution is appreciably weaker than the control test. The compatibility test indicates NQAS-6 could be compatible with the conventional additives in water-based drilling fluids, and the temperature resistance of modified starch was improved effectively. Meanwhile, the inhibitive mechanism was discussed through the particle distribution measurement.

Preparation and performance of amine-tartaric salt as potential clay swelling inhibitor

A series of small molecular clay swelling inhibitor was prepared with tartaric acid and amines, presented as amine-tartaric salts (ATS). The inhibitor was screened based on the linear expansion rate of bentonite. The results show that the inhibitor prepared with tartaric acid and triethylenetetramine with the mole ratio of 1:1 (named as ATS-4) is the best inhibitor of the hydration expansion and dispersion of bentonite. The inhibitive properties of ATS-4 were evaluated by various methods, including clay linear swelling tests, anti-swelling tests, mud ball immersing tests, mud-making inhibition experiments and particle distribution measurements etc. The results show that ATS-4 has superior performance to inhibit the hydration swelling and dispersion of clays by controlling the particle size of clay. On the other hand, the bentonite linear expansion rate in 0.5% ATS-4 aqueous solution is much lower than that of others, and the hydration expansion degree of the mud ball in ATS-4 aqueous solution is appreciably weaker than the control test, and it is compatible with the conventional additives in water-based drilling fluids. Then, the inhibition mechanism of the amine-tartaric salt was well discussed based on thermogravimetric analysis (TGA), scanning electron microscope (SEM), X-ray diffraction analysis (XRD), single crystal X-ray diffraction and ion exchange tests.

A Novel Method for Determining the Degree of Clay Swelling in Clay–Polymer–Water Systems

The effectiveness of various clay-shale swelling inhibitors was evaluated, and the hydration mechanism was studied using information on the contents of adsorbed water in clay–polymer–water systems. Quantitative analysis was performed by UV-photodetection and thermogravimetric analysis. The evaluation of the degree of shale hydration could provide new ideas for well designs, and information regarding the most effective and ecologically friendly swelling inhibitors.

Influence of Clay Swelling Inhibitor in Filtration Properties of Water-Based Drilling Fluids

This work aims to evaluate the influence of the clay swelling inhibitor in the filtration properties of water-based drilling fluids. Drilling fluids were prepared with and without adding potassium citrate clay inhibitor. The following additives were used in the composition of the fluid: viscosity agent (xanthan gum), filtrate reducer (starch and low viscosity carboxymethylcellulose (CMC LV)), antifoam, bactericide, sealant (calcite), lubricant and pH controller. The concentration of inhibitor was used of 15, 20, 25 and 30 g/ 350 mL of water. We determined the filtration properties (filtrate volume (FV), spurt loss (SL), cake thickness (CT) and permeability (K)) of drilling fluids. According to the results, it was concluded that: (i) adding the inhibitor to the fluid promoted reduction of FV and K of fluids containing starch in the composition and (ii) the inhibitor promoted satisfactory reductions in the CT and increased of SL for all the studied fluids. Finally, the inhibited fluids prepared with higher concentrations of starch, CMC LV, calcite and potassium citrate than 25 g/ 350 mL of water showed the best performance compared to FV and SL.

Synergistic stabilization of shale by a mixture of polyamidoamine dendrimers modified bentonite with various generations in water-based drilling fluid

The amine terminated polyamidoamine (PAMAM) dendrimers were investigated as potential shale stabilizers for the first time. Its inhibitive properties were characterized by a bentonite inhibition test and a shale cuttings dispersion test. The interaction between PAMAM dendrimers of various generations and sodium bentonite was examined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The hydration and dispersion of shale can be effectively inhibited with PAMAM dendrimers. The decrease of pH value in the dendrimer aqueous solution improved the inhibitive performance. For lower generations of dendrimer growth (G0 to G3), the inhibitive level decreased with the increase of generation. For higher generations (G4, G5), the inhibitive level increased with the increase of generation. Low generation PAMAM dendrimers could penetrate into the clay interlayer space, but exhibited highly oblate intercalation behaviors. G0 intercalated into the interlayer space with a monolayer conformation as concentration increased, while G1, G2, G3 and G4 intercalated into the interlayer space with monolayer arrangement at low concentrations, and mixed phase orientation at high concentrations. G5 could not fully intercalate into the interlayer space due to the steric hindrance. According to the interaction between PAMAM and clay, effective internal and external inhibition on shale hydration and dispersion could be obtained with the combination of low generation G0 and high generation G5. A new water-based drilling fluid including G0 as shale swelling inhibitor and G5 as shale dispersion inhibitor was established and exhibited excellent inhibitive properties.

Synthesis and Evaluation of Carboxymethyl Glucoside as Montmorillonite Swelling Inhibitor

Methylglucoside (MEG) has been used in the water-based mud with fine montmorillonite (MMT) swelling inhibition, but it still has such shortages as large concentration and low thermostability. In this work, carboxymethyl glucoside (CMG) was synthesized with glucose and sodium chloroacetate and used as swelling inhibitor. The inhibition of CMG against clay swelling was investigated by MMT linear expansion test, mud ball immersing test and bentonite inhibition test. The results showed that the CMG has a good inhibition to the hydration swelling and dispersion of MMT. Under lower concentrations, the linear expansion rate of MMT in CMG solution is much lower than that of MEG, and the hydration expansion degree of the mud ball in the CMG solution was significantly inhibited. The characterizations of physicalchemical properties of particle, analysized by thermogravimetric analysis and scanning electron microscopy revealed that CMG plays a great role in preventing water from absorbing and keeps MMT in large particle size.

INFLUÊNCIA DE SAIS DE POTÁSSIO COMO INIBIDORES DE INCHAMENTO DE FOLHELHOS NO DESEMPENHO DE FLUIDOS DE PERFURAÇÃO POLIMÉRICOS

Stability of well in layer with shale is strongly influenced by the kind of drilling fluid used in the drilling activity. Therefore, when its praticle the use of aqueous fluids, then it is need to use swelling inhibitors to avoid the expansion of such formations shows in water presence. Actually, new products chlorine-free has been tested due to enviroment concern. Thus, the aim of this work is to evaluate the influence of chlorine-free inhibitors in the rheological and filtration properties and polymeric drilling fluid toxicity with the potential to be applied in drilling oil wells that have reactive-formations. From the evaluation of the results, it was verified that the fluids developed with chlorine-free inhibitors showed different rheological and filtration properties. This behavior is related to the different dosages of K+ ion (the potassium ion promotes the control of the swelling reaction formations) present in the studied fluids. The results also indicated that all fluids are non-toxic

Expansion of Natural Na+– and Ca2+–Montmorillonites in the Presence of NaCl and Surfactant Solutions

Two natural smectites, Na+– and Ca2+–montmorillonites, were contacted with NaCl solutions at concentrations between 0.05 and 0.70 mol/L; further, KCl as a swelling inhibitor and an alkylamido betaine and α-olefin sulfonate mixture used as a foaming surfactant for the water alternating gas (WAG) process were added separately to the saline solutions. The mean crystalline swelling and the distribution of the particle thickness arranged as a pile of sheets and oriented perpendicular to the 001 diffraction direction were calculated from the X-ray diffractograms and according to literature methods; the mean crystalline swelling was tested against Monte Carlo molecular simulation results from our previous works. Distribution of the clay particle thickness indicates the fuzziness of the transition between the crystalline and osmotic swelling; this method clearly shows the presence of osmotic swelling not detected on the basis of the other methods. The degree of osmotic swelling depends upon the nature of clay; it...

Rule based design of clay-swelling inhibitors

In oil and gas drilling operations, drilling fluids perform essential tasks such as lubricating the drill bit, providing hydrostatic pressure and removing drill cuttings. One important function of the drilling fluid is to stop compacted clay minerals, commonly encountered in drilling operations, from taking up water from the drilling fluids and consequently swelling. Such a scenario can have an adverse impact on drilling operations and may lead to significantly increased oil well construction costs. With increasingly stringent environmental guidelines determining which swelling inhibitors are available for use in the oilfield as drilling fluid additives, there is a need to fully understand the mechanisms of clay hydration in order to design new swelling inhibitors which conform to evolving regulations. Using a range of computational techniques and analysis, combined with known experimental results, we have devised a set of “rule-based” design criteria for clay-swelling inhibitors. To achieve this, we have formulated a hydration energy parameter, which assesses the changes in energy during the step-wise progression from mono- to bi- to trilayers of water in the clay sheet galleries. This parameter can be used to rationalise and predict the swelling profiles for clays containing both cationic and neutral clay swelling inhibitors. The rules we have devised are as follows: (i) Cationic inhibitors should be able to replace sodium ions in the interlayer. (ii) Cationic inhibitors should possess a water soluble, hydrophobic backbone. (iii) Cationic inhibitors should have primary di-amine or mono-quaternary amine functionality. (iv) Cationic inhibitors should have little alcohol functionality. (v) The hydrophobic backbone of the cationic inhibitor should be long enough to form a dense monolayer in the interlayer. (vi) For neutral inhibitors, the inhibitor should be a water soluble organic molecule of low molecular weight with well defined domains of relatively high hydrophobicity and small domains of hydrophobicity. Our “rule-based” criteria will facilitate the rational design of improved—and more environmentally acceptable—clay swelling inhibitors for oilfield drilling operations.

Cationization of field pea starch in salt-free aqueous suspension

Industrial production of cationic starches involves excessive amounts of costly and environmentally toxic salts (∼60%, starch dry weight basis) as swelling inhibitors. The present study investigated the preparation of cationic field pea starch using the reagent, 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC), substituting a commonly used salt, sodium sulfate, with natural sugars such as sucrose or glucose under alkaline conditions. The effects of sugar type and concentration on the degree of substitution were studied. At a concentration of 20% of the weight of starch solids both sucrose and glucose effectively prevented starch granule swelling. Under reaction conditions similar to those used in industrial processing, cationization of pea starch in the presence of sodium sulfate resulted in a degree of substitution and reaction efficiency approximately twice as high as sucrose and four times as high as glucose. For this reason, sucrose was investigated further as a more suitable alternative to sodium sulfate than glucose in the salt-free preparation of cationic starch. Optimization of reaction conditions such as temperature, pH, swelling inhibitor and cationic reagent concentrations using sucrose as the swelling inhibitor resulted in a cationic starch with a degree of substitution of 0.07, comparable to the 0.06 that was obtained using sodium sulfate. These results indicate that sucrose may be a viable alternative to sodium sulfate in the production of cationic pea starch.

Clay swelling inhibition mechanism of α,ω-diaminoalkanes in Portland Brownstone

Many clay-bearing sedimentary stones such as Portland Brownstone will swell when exposed to water, and this can generate damaging stresses as differential strains evolve during a wetting cycle. Current swelling inhibitors, consisting of α,ω-diaminoalkanes, can reduce swelling in Portland Brownstone up to 50%. In this study, through x-ray diffraction and swelling strain experiments, we demonstrate that the α,ω-diaminoalkanes inhibit swelling by substituting for interlayer cations and partially hydrophobicizing the interlayer, then rehydrating on subsequent wetting cycles. We also introduce the copper (II) ethylenediamine complex as a potential treatment for swelling inhibition.

Role of clay minerals in the physicomechanical deterioration of sandstone

Extensive weathering suffered by sandstone in natural outcrops as well as in historical buildings could be attributed among other mechanisms to the action of wetting and drying cycles. We have recently shown how to quantify the stresses generated during such cycles to determine whether damage can take place. This procedure is further developed in this paper and applied to the Tarifa sandstone, a sandstone with a 7 wt % content of clay minerals and used in the main façade of the church of San Mateo in Tarifa (Cádiz, Spain) for which the relevant material properties are measured. It is shown that tensile stresses during drying can cause cracking of thin elements and that shear forces can cause buckling of wetted surfaces more generally, eventually resulting in scaling and/or contour scaling. These predictions are supported by visual observations on the monument showing degradation patterns characteristic of those types of damage. Similar weathering forms have been observed in natural sandstone landscapes. Application of swelling inhibitors (e.g., cationic surfactants) that selectively adsorb on the clay basal planes, results in a substantial swelling reduction. This confirms that the swelling clays typically present in sandstone are pivotal for its weathering and indicates that swelling inhibitors are a potentially valuable treatment to prevent or minimize damage to stone. The circumstances that would lead to weathering are discussed in relation to sandstone material properties in the wet and dry state. Clay‐bearing stones are shown to exhibit softening during wetting, as well as viscoelastic stress relaxation, which is expected to limit the extent of damage. These results may aid in the better understanding of sandstone weathering both in nature and in urban environment and may help develop conservation methods to mitigate wetting/drying damage in ornamental sandstone or to prevent pore plugging in reservoir sandstones.

Improvement of the Dimensional Stability of Powder Injection Molded Compacts by Adding Swelling Inhibitor into the Debinding Solvent

Defects are frequently found in powder injection molded (PIM) compacts during solvent debinding due to the swelling of the binders. This problem can be alleviated by adjusting the composition of the debinding solvent. In this study, 10 vol pct swelling inhibitors were added into heptane, and the in-situ amounts of swelling and sagging of the specimen in the solvent were recorded using a noncontacting laser dilatometer. The results show that the addition of ethanol, 2-propanol, 1-butanol, and 1-pentanol reduced the amounts of swelling by 31, 21, 17, and 11 pct, respectively. This was because the small molecule alcohols, which do not dissolve paraffin wax (PW) or stearic acid (SA) in the binder system, could diffuse easily into the specimen and increased the portion of the swelling inhibitor inside. The amount of the extracted PW and SA also decreased, but only by 8.3, 6.1, 4.3, and 2.4 pct, respectively. The solubility parameters of 1-bromopropane (n-PB) and ethyl acetate (EA) are between those of heptane and alcohols, and they also yielded a slight reduction in the amounts of swelling by 6 and 11 pct, respectively. These results suggest that to reduce defects caused by binder swelling during solvent debinding, alcohols with high solubility parameters can be added into heptane without sacrificing significantly on the debinding rate.

Controlling Swelling of Portland Brownstone

AbstractMany clay-bearing sedimentary stones such as Portland Brownstone will swell when exposed to water, and this can generate damaging stresses as differential strains evolve during a wetting cycle. Current swelling inhibitors, consisting of α,ω-diaminoalkanes, can reduce swelling in Portland Brownstone up to 50%. In this study, through X-ray diffraction and swelling strain experiments, we demonstrate that the α,ω-diaminoalkanes inhibit swelling by substituting for interlayer cations and partially hydrophobicizing the interlayer, then rehydrating on subsequent wetting cycles. We also introduce the copper (II) ethylenediamine complex as a potential treatment for swelling inhibition.

Effects of Salts on the Reaction of Normal Corn Starch with Propylene Oxide

The objective of this research was to develop a greater understanding of the mechanism by which salts inhibit gelatinization of starch granules. Using hydroxypropylation of corn starch in the presence of sodium sulfate under conditions employed industrially as the control reaction, reactions with propylene oxide were done with different salts at levels that matched the control reaction in anion molal concentration, cation molal concentration, and total ion molal concentration. Salts used were selected based upon their position in the lyotropic series. Reactions were characterized by determining reaction efficiency and ion concentrations. Sodium and potassium citrates, salts exhibiting a strong lyotropic effect, were extremely effective as gelatinization inhibitors, but resulted in low reaction efficiency. Salts without a strong lyotropic effect (sodium and potassium chlorides) exhibited a weak protective effect, probably at least in part based upon generation of a Donnan potential. In the hydroxypropylation reaction, sodium citrate greatly reduced swelling; sodium chloride was ineffective as a swelling inhibitor, resulting in pasting of granules, and sodium sulfate allowed restricted swelling, most likely as a result of a moderate lyotropic effect and some generation of a Donnan potential. That reaction efficiency parallels granule swelling was confirmed.