Grouting Solutions Research Articles

Efficacy of soybean-derived crude extract in enzyme-induced carbonate precipitation as soil-improvement technique

Calcium carbonate precipitation using a urease enzyme, referred to herein as Enzyme-Induced Carbonate Precipitation (EICP) is a technique for soil improvement. In this technique, a mixed solution composed of reagents and the urease enzyme, which produces calcite, is utilized as the grouting material. Recently, alternative materials to the urease enzyme have been examined to resolve the cost issue of using the urease enzyme. In this study, several tests were conducted to compare commercial urease and soybean-derived crude urease. A comparison of their hydrolysis rates was done through urease activity tests. The microscopic structures and mineralogy of the precipitated materials, produced during various loading periods, were investigated through SEM and XRD analyses. Moreover, the reinforcing effect of the grouting solutions on the treated soil specimens was evaluated by measuring the unconfined compressive strength (UCS) of the treated samples. Interestingly, the precipitated CaCO3 was vaterite and calcite when using soybean urease, while it was mostly calcite when using the urease enzyme. Higher UCS values were obtained with the soybean urease samples because the precipitated CaCO3 seemed to be concentrated at the inter-grain contacts. It was concluded that soybean powder shows great efficacy as a replacement for commercially produced enzyme urease in soil-improvement techniques mediated by carbonate precipitation.

ДИСПЕРГАТОРЫ ДЛЯ БУРОВЫХ РАСТВОРОВ

Dispersants used in drilling technology to improve the technological performance of drilling and grouting solutions are considered. The comparative characteristics of the devices are given, their ad-vantages and disadvantages are listed

Numerical modeling for controlled compensation grouting

This article analyzes the numerical modeling of the stress-strain state of a gravity structure sand base during grouting works using the controlled compensation grouting technique. The modeling is performed using the finite element method and physical nonlinear soil models that take into account the Coulomb-Mohr strength condition. The modeling is done in the computational software JuliS as well as the universal software complex PC ZSoil. The goal of the research is to study the impacts of compensation grouting parameters on the elevation value of base slab. A model was created for the grout body as an expanding spheroid whose volume changes as cement grout is fed in the soil. The authors developed a grouting sequence for grouting solutions based on the location of grout body in the grouting pillar. It is more efficient to feed the grout starting from the lower grout body. The grouting solution feed mode is selected depending on the soil strength condition and accounting for the prevention of hydraulic fracture. As a result of the research, the initial subsidence of the soil on the daytime surface above the injection zone was obtained, which requires experimental confirmation and is a matter for discussion.

The corrosion behavior of borosilicate glass in the presence of cementitious waste forms.

Borosilicate glasses are widely used for radioactive waste disposal due to their ability to incorporate a variety of contaminants and radionuclides while exhibiting high durability in various disposal scenarios. This research evaluated the dissolution of borosilicate glass using both single-pass-flow-through (ASTM C1662-18) and product consistency test (ASTM C1285-21) methods with different solutions, including a cementitious-contacted water (called grout-contacted, GC, from this point) and solutions with varying levels of dissolved cementitious species such as Si, Ca, Al. The results indicated that the presence of Ca plays a crucial role in suppressing glass corrosion, as evidenced by the slower normalized dissolution rates, which were one order of magnitude lower for boron and two orders of magnitude lower for rhenium, observed in both Ca-amended and GC solutions compared to the pH 12 buffer solution. This effect is attributed to the formation of a dense, low-porosity, and strongly bonded calcium silicate hydrate (CSH) layer on the glass surface, which implies that a glass corrosion process is influenced by ion exchange involving alkali ions Na+, K+, Ca2+, and hydrogen-containing species. A small number of glass particles treated in the GC solution showed minor corrosion pits in the form of shallow craters with an average diameter of approximately 500 μm. This observation is correlated with a significant reduction, 2000 to 3000 times lower, in the cumulative volume of glass pores, indicating that smaller pore voids were "sealed" in the presence of Ca2+ ions, likely attributed to the formation of CSH precipitation or other corrosion products such as calcium carbonate saturated from the grout solution. These findings suggest that the presence of dissolved Ca in the GC solution can slow down the dissolution of borosilicate glass, contrary to the expected trend of higher dissolution rates resulting from exposure to high alkaline and thus higher pH solutions.

GROUTING SOLUTION FOR FIXING THE CASING OF THE WELL

The article discusses the use of spent bleach clays in the formulation of grouting solutions injected into the space between the casing and the wall of the well. A grouting solution is proposed, including Portland cement; selected clay for the production of motor oils, a filtration step-downer (CMC), a plasticizer - saponified cotton tar, water or an aqueous solution of a setting time accelerator- sodium chloride, a defoamer.

IMPROVING THE METHOD OF SELECTING BUFFER TO IMPROVE THE QUALITY OF WELL ANCHORING WITH THE USE HYDROCARBON-BASED DRILLING FLUID

Currently, when cementing casing strings, various formulations of buffer fluids are used, the choice of which is based on laboratory testing of its compatibility with specific drilling and grouting solutions. The development of market relations evolutionarily pushed manufacturers to obtain and use the most efficient, durable materials and technologies that meet the requirements of ISO 13500:2008 [11], ISO 10426-2:2003(R) [12].In foreign and Russian practice, leading oil and gas companies use integrated quality management systems. However, due to the influence of a number of socio-economic factors, there has been a sharp rise in the cost and reduction in the production of components, along with a continuous increase in the need for efficient materials in many industries. The use of components produced by domestic enterprises in industrial volumes makes them deficit-free, and in terms of price quite affordable and competitive raw materials [6].«RN-BashNIPIneft» LLC together with the «USPTU has developed a methodology to establish uniform requirements for the evaluation of buffer fluids for hydrocarbon-based drilling fluids when cementing casing strings. The methodological basis for achieving this goal is the concept of a systematic approach in the quality management of buffer fluids [8].

Investigation of impact resistance of grouting materials

Background: Cementing of the production column is an important stage of well completion, which in turn requires the correct selection of the formulation of grouting solutions that ensure the durability of well operation.
 Aim: In this article, the analysis of the main factors affecting the quality of well cementing at each stage is carried out, and the impact resistance of grouting materials in the bottom-hole zone of the well is considered in detail.
 Materials and methods: The method of assessing the impact resistance of grouting materials by the magnitude of impact strength is described.
 Results: The results of research work carried out on the basis of this method with reinforced grouting solutions used to increase the specific impact strength of cement stone are presented.
 Conclusion: Experimental studies have shown the effectiveness of polypropylene fiber and building micro-reinforcing fibers at concentrations of 0.25 and 0.5%.

Sedimentation-resistant and moderately expanding grouting composition

The results of the conducted studies allow us to conclude that an increase in the number of micelles per unit volume of the grouting solution will lead to an increase in its sedimentation stability. The desired effect can be achieved by increasing the concentrations of surfactants in the mixing fluid or by introducing an electrolyte. Since the presence of sites with adsorbed surfactant additive on the surface of the dispersed phase particles significantly changes the conditions for the formation of phase contacts, which, accordingly, will affect the properties of the hardening grouting system.

The effect of polymer-cement mortars with additives of aluminosilicate microspheres on the reservoir properties of exploration and production wells

The article shows that the use of lightweight grouting solution with hollow aluminosilicate microspheres can reduce the time and the cost of materials spent on securing exploration wells, ensure the rise of solution to the design height. Improved strength and fracturing of the stone ensures resistance to fracture during perforation, and a sufficiently strong bond can ensure tightness of the annulus in exploration and production wells.

Application of polyelectrolyte reagents for regulation of the properties of grouting solution

Application of polyelectrolyte reagents for regulation of the properties of grouting solution

Potentially of Soybean as Bio-Catalyst in Calcite Precipitation Methods for Improving the Strength of Sandy Soil

The biocementation-based soil improvement technique that has been recently developed is enzyme-induced calcite precipitation (EICP). Previous studies on the EICP technique used pure commercial urease enzyme as a reaction catalyst to precipitate calcite from urea and calcium chloride. However, pure commercial urease enzyme is inefficient for application on a large scale due to its high price. Therefore, studies reported that soybean is a potential alternative for pure commercial urease enzymes. This study evaluates the strength of sandy soil by treatment using EICP grouting solution with soybean extracts as the bio-catalyst. The extracts used in this study were obtained by filtration and centrifugation treatment. Based on the calcite mass quantification and precipitation ratio, 20 g/L soybean extract concentration in both treatments is used for treating the solution. Then, the unconfined compressive strength (UCS) tests were conducted to evaluate the increase of the strength of sandy soil. The maximum UCS value was obtained at the 28 days of curing time in both treatments. The centrifugation treatment has a higher UCS value with 65.6 kPa than the filtration treatment with 53.6 kPa. Thus, this study elucidated that soybean extract has a great potential to be a bio-catalyst in the calcite precipitation method.

Application of calcite precipitation method to increase the shear strength of peat soil

The organic elements in the peat soil promote the fibrous texture and high moisture content. As a result, it has high compressibility density, shear strength, and low bearing capacity. Several methods of peat soil improvement have been implemented but are less environmentally friendly. The calcite precipitation method is one of the alternative sustainable methods by depositing calcium carbonate (CaCO3). Soybean flour is used for the hydrolysis of urea, which causes the supply of calcium ions to precipitate calcium carbonate. The optimum composition of grouting solution consisting of 1 mol/L of reagent and 15 g/L and soybean is mixed into the soil. The shear strength parameters, namely the undrained shear strength (Cu) and internal friction angle, were evaluated by direct shear test. Soil with the treated solutions obtains Cu and internal friction angle of 49 kPa and 34°, respectively. On the other hand, Cu and internal friction angle have increased from the soil untreated soil by 34 kPa and 19°. This study elucidated that the calcite precipitated method have a great potential to improve the shear strength of organic soil.

Computer assisted optimal evaluation of grouting scheme in shallow tunnel through G1 method and GRA

In tunnel construction, grouting technology is an extremely important reinforcement method for improving the mechanical properties and increasing the strength of surrounding rock. This paper presents an optimization evaluation method of grouting scheme for advanced reinforcement in shallow tunnel based on G1 method and grey relational analysis (GRA). In the Haicang Subsea Tunnel Project of Xiamen, the four grouting schemes were optimized and analyzed through the previous optimization evaluation method, the most suitable solution is obtained as the full-control one-time grouting solution and the result has also been verified in practice.

Technological Capabilities of Well Cementing

Abstract Cementing of casing string is a final operation before the next stage of well construction; it provides maximum operational life of the well. Cementing of casing string is carried out with the use of technology, based on squeezing of the whole volume of drilling mud by special grouting composition. The main purposes of cementing include isolation of water-bearing horizon, strengthening of borehole walls in unconsolidated and unstable rocks. Well cementing process is divided into five subsequent operations. Firstly, grouting mixture is prepared in concrete mixers (cementing units) with necessary water-to-cement ratio and additives. Secondly, prepared grouting solution is injected in a well. Thirdly, the solution is squeezed into the space between the casing pipes and wellbore walls. Then it is necessary to wait until the cement sheath is hardened. And at last, quality control is carried out. For convenient transportation, the equipment for well cementing is installed on the truck chassis (KAMAZ, URAL and etc.). All components are poured in concrete mixer, then the water is added and everything is being mixed until formation of uniform mass, which is later pumped in a well. Oil and Gas Industry Safety Regulations say that «calculated endurance of casing string cementing should not exceed 75% of time of cement thickening, established by laboratory tests». Therefore, it is necessary to carry out all operations of injection of fluids into the well as soon as possible without any incompliances of the cementing technology. With cementing material used and its water-to-cement ratio of 0.5, the average time of cement thickening is 120 minutes, according to laboratory tests. Therefore, a set of operations of injection of fluids should not exceed 90 minutes.

ASYMPTOTICS OF THE FILTRATION PROBLEM WITH ALMOST CONSTANT COEFFICIENTS

During the construction of hydraulic and underground structures, a grout solution is pumped into the ground to create waterproof partitions. The liquid grout is filtered in the porous rock and clogs the pores when hardened. The mathematical model of deep bed filtration describes the transfer of suspension particles and colloids by a fluid flow through the pores of a rock. For a one-dimensional filtration problem in a homogeneous porous medium with almost constant coefficients, an asymptotic solution is constructed. The asymptotics is compared with the numerical solution.

Performance analysis of steel slag powder-coal gangue grouting material

In this paper, coal gangue soil, steel slag powder and polycarboxylic acid superplasticizer with different dosages were combined into ordinary Portland cement. Grouting solution was prepared according to different water-cement ratios and solidified under standard conditions. Through orthogonal experiments, the influence of different dosages on the rate of grout stones and the compressive strength of stones in different ages was studied. The experimental results show that the increase in the amount of coal gangue will lead to the decrease of the slurry stone first and then increase, and the compressive strength will decrease. The increase in the amount of steel slag powder reduces the stone rate and compressive strength of the slurry.

Research of technological properties of the composition of binding binders, modified with waste of processing of petroleum bituminous rocks

The paper deals with the issues of technology of grouting binders of silicate materials with the use of waste from the processing of petroleum bituminous rocks. The optimal compositions of grouting solutions with the use of waste from the processing of PBR were studied.The stability of the samples in aggressive environments of low-and high-base calcium hydrosilicates was studied. Technological processes for the production of grouting binders based on waste from the processing of PBR were justified and developed.Grouting compositions, characterized by high quality were developed. The positive effect of mixing and storage of the tested cement mixtures containing up to 50% of PBR waste with sulfate solutions of Na 2SO 4 and MgSO4 salts on the studied technical characteristics of the grouting solution and cement stone was established.A significant result is an improvement in the setting performance, an increase in strength without a significant deterioration in the adhesion of the cement stone to the drive pipe at a 5% salt concentration.The research results provide recommendations for the development of weighted grouting cements using technogenic materials containing an increased amount of iron oxide.

The Utilization of Milk as a Catalyst Material in Enzyme-Mediated Calcite Precipitation (EMCP) for Crack-Healing in Concrete

This study discussed the applicability of the calcite precipitation method to repair the concrete's crack. The grouting solution of Enzyme-Mediated Calcite Precipitation (EMCP) was modified by adding milk as a catalyst in calcite formation. Cracks in concrete samples were made when the concrete was 28 days with a width of 0.1-0.3 mm. The EMCP solution composed of urease, urea, CaCl2, and milk was injected into the cracked concrete sample, and its effect on permeability and compressive strength tests were evaluated. The result shows that the optimum composition of milk used in the formation of calcite had a concentration of 5 g/L with an initial preparation temperature of 70oC, which produced 26% higher than the initial EMCP solution. The mechanical test results show that the reduction of coefficient of permeability of 92.23% compared to the cracked sample and the improve strength up to 98.75% of the non-cracked sample were obtained by three circles injection. This study elucidated that milk utilization as a catalyst material in repairing cracks with the EMCP method is a potential method for crack-healing concrete.

Evaluation of carbonate precipitation methods for improving the strength of peat soil

This research was carried out to evaluate the potential improvement of the strength of peat soil with the carbonate precipitation method. The grouting solution’s optimum combination was determined and mixed to soil sample with a various density of 1.15, 1.20, and 1.25 g/cm3. The mass of precipitated carbonate within the soil and its effect on peat soil’s increasing strength was evaluated by the unconfined compression (UCS) test. The mass of precipitated carbonate within peat soil was evaluated by acid leaching method, respectively. The UCS test showed that the strength of treated peat soil had improved significantly. The treatment using carbonate precipitation brings about an improvement of 38% to 48% compared to the untreated sample. The maximum strength of 375.12 kPa was achieved at a density of 1.25 g/cm3. The result of this study also indicated that the initial density has no significant impact on the improvement of precipitated carbonate in peat soil. A relatively similar precipitated carbonate of 2-3% of soil mass was formed in the entire soil sample. This study elucidated that the carbonate precipitation method is a potential method to improve the peat soil’s shear strength.

Utilization of soybean powder as the additional material on calcite precipitation method for improving the strength of liquefiable soil

This research was carried out to evaluate the addition of soybean in the calcite precipitation method as a soil improvement technique. The evaluated soil was poorly graded and liquefiable sand with a specific gravity of 2.69. The precipitation test was performed to obtain the optimum concentration of grouting solution. Various combinations of soybean and reagent composed of urea and calcium chloride were prepared and were applied to sandy soil through the percolation method. The impacts of soybean on improving the shear strength of treated soil were examined using unconfined compression tests. The result of this study shows that the use of soybean shows a significant enhancement of the soil strength. The strength of 168 kPa was achieved when 60 g/L of soybean added to the grouting solution, which is also promoted a calcite amount of 3% of the soil mass. This research elucidated that the addition of soybean in the calcite precipitation technique is possible to optimize the calcite precipitation method’s applicability as the soil improvement technique.