scholarly journals An Experimental Assessment of Iraqi Local Cement and Cement Slurry Design for Iraqi Oil Wells Using Cemcade

2021 ◽  
Vol 22 (1) ◽  
pp. 1-13
Author(s):  
Amel Habeeb Assi ◽  
Faleh H.M. Almehdawi

This effort is related to describe and assess the performance of the Iraqi cement sample planned for oil well-cementing jobs in Iraq. In this paper, major cementing properties which are thickening time, compressive strength, and free water in addition to the rheological properties and filtration of cement slurry underneath definite circumstances are experimentally tested. The consequences point to that the Iraqi cement after special additives encounter the requests of the API standards and can consequently is used in cementing jobs for oil wells. At this research, there is a comparative investigation established on experimental work on the effectiveness of some additives that considered as waste materials which are silica fume, bauxite, and glass powder, and other conventional additives which are: (SCR -100 Retarder, HR-5, FWCA, Hollow Glass Spheres (HGS) and Halad-9) that currently used in our fields on local Iraqi cement and putting foreign cement results as a governor. Chemical analysis for Iraqi cement, imported cement, and waste materials samples was determined using the X-ray fluorescence (XRF) technique and found minor differences in composition between those samples and depending on the results of X-ray, we selecting the appropriate additives to prepare cement slurry samples. The X-ray fluorescence (XRF) results show that Iraqi Cement has a low value of silica which is about 18.63% while Omani cement about 37.58%. This research examined the potential of micro silica, bauxite, and waste glass powder to produce sustainable cement slurry. The results showed that adding micro silica and bauxite enhances the performance of Iraqi cement but also leads to a slight decrease in thickening time. To avoid this problem, Superplasticizer is used to make the process of cement pumping more easily, in other words, increase thickening time and increase compressive strength. Furthermore, adding glass powder increase the value of compressive strength. Both additives (waste and conventional) are used for the slurry design for achieving better slurry properties, but waste additives increase and enhance Iraqi cement performance than conventional additives, in other words, making it more effective than commercial cement. Depending on the results of the compressive strength test, the optimal concentration of the waste materials used in this research was found, and then the optimal concentration was used to prepare cement samples. The results showed that the use of waste materials to prepare cement slurry is a promising way to improve the efficiency of cement work and to reduce the negative environmental impact resulting from the industry. The results of the program CemCADE proved to be the sample A and C showed good performance through high cement bonding and ideal distribution of fluids designed to accomplish the cementing process.

2020 ◽  
Vol 53 (2E) ◽  
pp. 62-73
Author(s):  
Amel Assi

The cement slurry is a mixture of cement, water and additives which is established at the surface for injecting inside hole. The compressive strength is considered the most important properties of slurry for testing the slurry reliability and is the ability of slurry to resist deformation and formation fluids. Compressive strength is governed by the sort of raw materials that include additives, cement structure, and exposure circumstances. In this work, we use micro silica like pozzolanic materials. Silica fume is very fine noncrystalline substantial. Silica fume can be utilized like material for supplemental cementations for increasing the compressive strength and durability of cement. Silica fume has very fine particles size less than 1 micron and by an average of about 0.1 microns, about 100 times slighter than particles of cement. We are adding 0%, 5%, 10%, 15%, 20% and 25% micro silica by wt. of cement. The results showed that adding micro silica enhance the performance of Iraqi cement but also leads to a slight decrease in thickening time. To avoid this problem, super plasticizer is used to make the process of cement pumping more easily, in other words, increase thickening time and increase compressive strength. The experimental work showed that adding micro silica leads to reduce free water and this property is very important through horizontal drilling. X-ray fluorescence technique delivers beneficial elemental information about the chemical structure of Iraqi cement to help us use it without causing damage through the cementing job. In this paper, some outlines of the XRF device and its main applications are presented. By using X-ray fluorescence analysis, we detect the problem of Iraqi cement and solve it in this paper to use it at cementing jobs in the Iraqi field instead of using imported cement.


2021 ◽  
pp. 147-156
Author(s):  
Ali M. Hadi ◽  
Ayad A. Al-Haleem

Cement is a major component in oil and gas drilling operations that is used to maintain the integrity of boreholes by preventing the movement of formation fluids through the annular space and outside the casing. In 2019, Iraq National Oil Company ordered all international oil and gas companies which are working in Iraq to use Iraqi cement (made in Iraq) in all Iraqi oil fields; however, the X-ray fluorescence (XRF) and compressive strength results in this study show that this cement is not matching with American Petroleum Institute (API) standards. During this study, barolift was used to improve the properties of Iraqi cement used in oil wells at high pressure and high temperature (HPHT). Barolift (1 g) was added to cement admixture to evaluate its influence on improving the performance of cement, mainly related to the property of toughness.  Primarily, the quality and quantity of cement contents were determined using X-ray fluorescence. Experiments were conducted to examine the characteristics of the base cement and the cement system containing 1g of barolift, such as thickening time, free water, compressive strength, and porosity. X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were conducted for analyzing the microstructure of cement powder. The experimental results showed that barolift acted as a retarder and improved the thickening time, slightly increased the free water, enhanced the mechanical properties, reduced the porosity, and aided in scheming new cement slurry to withstand the HPHT conditions. Microstructure analysis showed that barolift particles blocked the capillaries by filling cement spaces and, thus, a denser and stricter cement network was achieved.


2013 ◽  
Vol 787 ◽  
pp. 222-227 ◽  
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Sandeep Kumar ◽  
Ahmed A.I. Elrayah

At present, high temperature oil wells are known as the most problematic for cementing operation due to limitations of polymer. The polymers are significantly used as mutlifunctional additives for improving the properties of cement slurry. At high temperature, viscosity of polymer decreases and unable to obtained desired properties of cement slurry. It becomes then major cause of fluid loss and gas migration during cementing operations. Thus, it necessitates for polymers that can able to enhance viscosity of slurry at elevated temperatures. This paper is aiming to study Hydroxypropylmethylcellulose (HPMC) polymer at high temperature that is able to increase the viscosity at elevated temperature. In response, experiments were conducted to characterize rheological properties of HPMC at different temperatures (30 to 100 °C). Then it was incorporated as multifunctional additive in cement slurry for determining API properties (fluid loss, free water, thickening time and compressive strength). It was observed that HPMC polymer has remarkable rheological properties that can have higher viscosity with respect to high temperatures. The best concentration of HPMC was found from 0.30 to 0.50 gallon per sack. This concentration showed minimal fluid loss, zero free water, high compressive strength and wide range of thickening time in cement slurry. The results signified that HPMC polymer is becoming multifunctional additive in cement slurry to improve the API properties of cement slurry and unlock high temperature oil wells for cementing operations.


2019 ◽  
Vol 828 ◽  
pp. 14-17
Author(s):  
Malgorzata Ulewicz ◽  
Jakub Jura

The preliminary results of utilization of fly and bottom ash from combustion of biomass for the produce of cement mortars has been presented. Currently, this waste are deposited in industrial waste landfills. The chemical composition of waste materials was determined using X-ray fluorescence (spectrometer ARL Advant 'XP). ). In the studies sand was replaced by mix of fly and bottom ash from the combustion of biomass in an amount of 10-30% by weight of cement CEM I 42.5 R (Cemex). The obtained cement mortar concrete were subjected to microscopic examination (LEO Electron Microscopy Ltd.) and their compressive strength (PN-EN-196-1), frost resistance (PN-EN 1015-11 and PN-B -04500 ) and absorbability (PN-85/B-04500) were identified. The obtained results showed, the replacement of the cement by mix ashes from combustion of biomass reduce consumption of raw materials and will have a good influence on the environment.


2014 ◽  
Vol 692 ◽  
pp. 433-438 ◽  
Author(s):  
Jing Fu Zhang ◽  
Jin Long Yang ◽  
Kai Liu ◽  
Bo Wang ◽  
Rui Xue Hou

Carbon dioxide CO2could corrode the oil well cement paste matrix under agreeable moisture and pressure condition in deep oil wells, which could decrease the compressive strength and damage the annular seal reliability of cement paste matrix. The problem of oil well cement paste matrix corrosion by CO2was researched in the paper for obtain the feasible corrosion prevention technical measures. The microstructure and compressive strength of corroded cement paste matrix were examined by scanning electron microscopeSEMand strength test instrument etc. under different corrosion conditions. The mechanism and effect law of corrosion on oil well cement paste matrix by CO2were analyzed. And the suitable method to protect CO2corrosion in deep oil wells was explored. The results show that the corrosion mechanism of cement paste matrix by CO2was that the wetting phase CO2could generate chemical reaction with original hydration products produced from cement hydration, which CaCO3were developed and the original composition and microstructure of cement paste matrix were destroyed. The compressive strength of corrosion cement paste matrix always was lower than that of un-corrosion cement paste matrix. The compressive strength of corrosion cement paste matrix decreased with increase of curing temperature and differential pressure. The corroded degree of cement paste matrix was intimately related with the compositions of cement slurry. Developing and design anti-corrosive cement slurry should base on effectively improving the compact degree and original strength of cement paste matrix. The compounding additive R designed in the paper could effectively improve the anti-corrosive ability of cement slurry.


2017 ◽  
Vol 6 (1) ◽  
pp. 38-43
Author(s):  
Novrianti Novrianti ◽  
Mursyidah Umar

The cementing process can determine successful oil well when producing oil to the surface. Planning the time required for the cement suspension to achieve consistency of 100 UC (unit of consistency) or thickening time and the maximum limit of water content used is the nature of cement slurry that affect the quality of cement. The addition of coconut shell charcoal with variation of heating temperature 400 0C, 500 0C, 600 0C, 700 0C, 800 0C, 900 0C to the basic cement was done in this study to determine the effect of heating temperature of coconut shell charcoal to thickening time and free water cement drilling. This experimental study uses an additive material derived from coconut shell charcoal. This experiment begins by preparing a cement sample with a coconut shell charcoal concentration of 1%. The coconut shell charcoal used has different heating temperatures of 400 0C, 500 0C, 600 0C, 700 0C, 800 0C, 900 0C. Suspense cement is made by mixing G grade cement, water, bentonite, CaCl2 and coconut shell charcoal. Thickening time test using atmospheric equipment consistometer and measuring cups used to determine the value of free water. The results showed that the thickening time and free water values ​​were influenced by the heating temperature of coconut shell charcoal. The higher coconut shell charcoal temperature used in the cement suspension make thickening time of the cement suspension becomes shorter. The optimum heating temperature of coconut shell charcoal is 700 0C with thickening time of 1 hour 38 seconds 52 seconds and free water 1.2 mL.


2019 ◽  
Vol 10 (2) ◽  
pp. 319-325
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Khalil Rehman Memon ◽  
Javed Khan

AbstractCellulose-based polymers have been successfully used in many areas of petroleum engineering especially in enhanced oil recovery drilling fluid, fracturing and cementing. This paper presents the application of cellulose-based polymer in oil well cementing. These polymers work as multifunctional additive in cement slurry that reduce the quantity of additives and lessen the operational cost of cementing operation. The viscosity of cellulose polymers such as hydroxyethyl cellulose (HEC), carboxymethylcellulose (CMC) and hydroxypropyl methylcellulose (HPMC) has been determined at various temperatures to evaluate the thermal degradation. Moreover, polymers are incorporated in cement slurry to evaluate the properties and affect in cement slurry at 90 °C. The API properties like rheology, free water separation, fluid loss and compressive strength of slurries with and without polymer have been determined at 90 °C. The experimental results showed that the viscosity of HPMC polymer was enhanced at 90 °C than other cellulose-based polymers. The comparative and experimental analyses showed that the implementation of cellulose-based polymers improves the API properties of cement slurry at 90 °C. The increased viscosity of these polymers showed high rheology that was adjusted by adding dispersant which optimizes the rheology of slurry. Further, improved API properties, i.e., zero free water separation, none sedimentation, less than 50 ml/30 min fluid loss and high compressive strength, were obtained through HEC, CMC and HPMC polymer. It is concluded that cellulose-based polymers are efficient and effective in cement slurry that work as multifunctional additive and improve API properties and cement durability. The cellulose-based polymers work as multifunctional additive that reduces the quantity of other additives in cement slurry and ultimately reduces the operational cost of cementing operation. The comparative analysis of this study opens the window for petroleum industry for proper selection of cellulose-based polymer in designing of cement slurry.


2021 ◽  
Vol 11 (2) ◽  
pp. 30-48
Author(s):  
Amel Habeeb Assi ◽  
Faleh H. M. Almahdawi ◽  
Qasim Abdulridha Khalti

The reinforced fiberglass in cement slurry reflects the effect on its properties compared to usual additives. Fiberglass is typically used in cement slurry design for one or another of the following goals: (Earth earthquake, bearing storage, and with differential stresses, to enhance cement durability and increase its compressive strength). The main goal is to use glass fiber and ground fiberglass to improve the tensile strength and moderate compressive strength significantly. On the other hand, the use of glass fibers led to a slight increase in the value of thickening time, which is a desirable effect. Eleven glass fiber samples and milled glass fiber were used to show these materials' effect on Iraqi cement with (0.125, 0.25, 0.5, 0.75, 1, and 2) % of cement weight. Those tests used to study cement slurry‟s following properties were compressive strength, thickening time, rheology properties of free water, filtering, and density. These evaluations showed that slurries with less than 1% fiber content gave a higher compressive strength than a sample containing more than 1% glass fiber. However, the slurry mixed with equal or less than 1% milled glass fiber is higher compressive than the sample mixed with more than 1% milled glass fiber. So the optimal concentration for glass fiber is less than 1% by weight of cement (BWOC); either for milled glass fiber, it is less or equal to 1% BWOC. Both materials contributed to increasing the compressive strength of the cement. However, attention must be paid to the idealThis work is licensed under a Creative Commons Attribution 4.0 International License. concentration that should be added during the cement slurry preparation because if we use these two materials carelessly for the ideal concentration, this leads to the collapse and bombardment of the resistance of the cement rock. In other words, the collapse of cement resistance and causing problems during the cementing process.


2019 ◽  
Vol 10 (3) ◽  
pp. 1097-1107 ◽  
Author(s):  
Salaheldin Elkatatny ◽  
Rahul Gajbhiye ◽  
Anas Ahmed ◽  
Ahmed Abdulhamid Mahmoud

AbstractDurability and long-term integrity of oil well cement are the most important parameters to be considered while designing the cement slurry, especially in the high-pressure and high-temperature (HPHT) environments. In this study, the effect of adding the polypropylene fiber (PPF) to Saudi Class G cement is evaluated under HPHT conditions. The effect of the PPF on the cement compressive and tensile strength, thickening time, density, free water, porosity, and permeability was studied. The effect of the PPF particles on the cement sheath microstructure was studied through powder X-ray diffraction (XRD) and scanning electron microscope. The results obtained showed that PPF did not affect the cement rheology, density, and free water. The addition of PPF considerably decreased the thickening time and improved the tensile and compressive strength of the cement. 0.75% by weight of cement (BWOC) of PPF reduced the thickening time by 75%, from 317 to 78 min. The compressive strength of the cement increased by 17.8% after adding 0.5% BWOC of PPF, while the tensile strength increased by 18% when 0.75% of PPF is used which is attributed to the formation of stable forms of calcium silicate hydrates because of the ability of PPF to accelerate cement hydration process as indicated by the XRD results. The ability of the PPF to decrease the cement thickening time along with its ability to improve the cement strength suggests the use of PPF as an alternative for silica floor in shallow wells where a reduction in thickening time will decrease the wait on cement time. Porosity and permeability of the base cement were also decreased by incorporating PPF because of the pores filling effect of PPF particles as indicated by the microstructure analysis.


2018 ◽  
Vol 15 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Somia Bechar ◽  
Djamal Zerrouki

PurposeWells’ cementing is an important and costly step in the engineering sector for oil and gas well. The purpose of this study was to investigate the use of Algerian natural pozzolan (NP) in order to evaluate the influence of partial substitution of class G cement on slurry properties.Design/methodology/approachNP was characterized by X-ray fluorescence (XRF), scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) and Fourier-transform infra-red spectrometry (FTIR). Their pozzolanic activity was evaluated by measuring the electrical conductivity in aqueous suspensions of pozzolan/calcium hydroxide. The replacement ration cement/NP was 10, 20 and 30 per cent, and the rheological behaviour, compressive strength properties at different ages, elastic properties, X-ray diffraction analysis, rapid chloride penetration, porosity and permeability of all slurries were investigated and compared with a standard sample.FindingsThe obtained results indicated that the replacement with 20 per cent by weight of cement at 21 and 28 days had a higher compressive strength (+30.62 per cent) and lower chloride penetration.Originality/valueThe results show the potential of the use of locally available NP in well cementing.


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