scholarly journals Improving the Iraqi Oil Well Cement Properties Using Barolift: an Experimental Investigation

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.

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.


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.


2014 ◽  
Vol 34 (5) ◽  
pp. 405-413
Author(s):  
Xianru He ◽  
Qian Chen ◽  
Chunhui Feng ◽  
Liang Wang ◽  
Hailong Hou

Abstract High performance cement slurry polymer modifiers are increasingly in demand in the cementing process of oil and gas. A new polymer modifier with outstanding fluid loss control and high strength and toughness was synthesized by the main monomers butyl acrylate (BA), methyl methacrylate (MMA), acrylamide (AM), the functional monomers vinyltriethoxysilane (VTS), glycidyl methacrylate (GMA) and the initiator of ammonium persulfate (APS) through emulsion polymerization. By using Fourier transform infrared (FTIR) spectrometer, a laser particle analyzer, a scanning electron microscope and a differential scanning calorimeter, we studied the mechanism of fluid loss control and microstructure of polymer latex cement slurries. The experimental results showed that the copolymer could be crosslinked at 160°C and have the lowest fluid loss control, 12 ml, when the polymer content reached 5%. Acrylate latex modified by the silane coupling agent VTS had excellent performance on fluid loss control, as well as mechanical properties for oil well cement. These results have a potential significant value for the development of a new polymer cement modifier with high thermal stability and durability.


Author(s):  
George Kwatia ◽  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu

Abstract Cementing operations in deepwater exhibit many challenges worldwide due to shallow flows. Cement sheath integrity and durability play key roles in the oil and gas industry, particularly during drilling and completion stages. Cement sealability serves in maintaining the well integrity by preventing fluid migration to surface and adjacent formations. Failure of cement to seal the annulus can lead to serious dilemmas that may result in loss of well integrity. Gas migration through cemented annulus has been a major issue in the oil and gas industry for decades. Anti-gas migration additives are usually mixed with the cement slurry to combat and prevent gas migration. In fact, these additives enhance and improve the cement sealability, bonding, and serve in preventing microannuli evolution. Cement sealability can be assessed and evaluated by their ability to seal and prevent any leakage through and around the cemented annulus. Few laboratory studies have been conducted to evaluate the sealability of oil well cement. In this study, a setup was built to simulate the gas migration through and around the cement. A series of experiments were conducted on these setups to examine the cement sealability of neat Class H cement and also to evaluate the effect of anti-gas migration additives on the cement sealability. Different additives were used in this setup such as microsilica, fly ash, nanomaterials and latex. Experiments conducted in this work revealed that the cement (without anti-gas migration additive) lack the ability to seal the annulus. Cement slurries prepared with latex improved the cement sealability and mitigated gas migration for a longer time compared to the other slurries. The cement slurry formulated with a commercial additive completely prevented gas migration and proved to be a gas tight. Also, it was found that slurries with short gas transit times have a decent potential to mitigate gas migration, and this depends on the additives used to prepare the cement slurry.


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.


2019 ◽  
Vol 11 (23) ◽  
pp. 6776 ◽  
Author(s):  
Abdulmalek Ahmed ◽  
Ahmed Abdulhamid Mahmoud ◽  
Salaheldin Elkatatny ◽  
Weiqing Chen

In deep hydrocarbon development wells, cement slurry with high density is required to effectively balance the high-pressure formations. The increase in the slurry density could be achieved by adding different heavy materials. In this study, the effect of the weighting materials (barite, hematite, and ilmenite) on the properties of Saudi Class G cement matrix of vertical homogeneity, compressive strength, porosity, and permeability was evaluated. Three cement slurries were weighted with barite, hematite, and ilmenite, and cured at 294 °F and 3000 psi for 24 h. All slurries have the same concentration of the different additives except the weighting material. The amount of weighting material used in every slurry was determined based on the targeted density of 18 lbm/gal. The results of this study revealed that the most vertically homogenous cement matrix was the ilmenite-weighted sample with a vertical variation of 17.6% compared to 20.2 and 24.8% for hematite- and barite-weighted cement, respectively. This is attributed to the small particle size of the ilmenite. The medical computerized tomography (CT) scan confirmed that the ilmenite-weighted sample is the most homogeneous, with a narrow range of density variation vertically along the sample. Hematite-weighted cement showed the highest compressive strength of 55.3 MPa, and the barite- and ilmenite-weighted cement compressive strengths are each 18.4 and 36.7% less than the compressive strength of the hematite-weighted cement, respectively. Barite-weighted cement has the lowest porosity and permeability of 6.1% and 18.9 mD, respectively. The maximum particle size of ilmenite used in this study is less than 42 μm to ensure no abrasion effect on the drilling system, and it minimized the solids segregation while maintaining a compressive strength that is higher than the minimum acceptable strength, which is the recommended weighting material for Saudi Class G cement.


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.


2014 ◽  
Vol 974 ◽  
pp. 26-32
Author(s):  
N. Alias ◽  
M.M.M. Nawang ◽  
N.A. Ghazali ◽  
T.A.T. Mohd ◽  
S.F.A. Manaf ◽  
...  

Cement is an important part in oil and gas well completion. A high quality of cement is required to seal hydraulic pressure between casing and borehole formation. Cement additives were used to enhance the cement properties such as thickening time, compressive strength, porosity and permeability of the cement. Currently, the commercial additives were imported and the price is keep increasing year by year. Therefore, the researchers were continuously looking for potential additives such as nanoparticle to improve the cement properties. This paper presents the effect nanosilica on compressive strength and porosity of oil well cement type G. In this study, two type of nanosilica were used, synthesis nanosilica from rice husk ash (RHA) and commercial nanosilica. The synthesized nanosilica was characterized using fourier transform infrared spectroscopy (FTIR), X-ray flouresece (XRF) and Field Emission Scanning Electron Microscopy (FESEM). All the experiments were conducted using API standard procedures and specifications. Based on the results, compressive strength of cement slurries was improved from 2600 psi to 2800 psi for 8-hours curing, when the amount of nanosilica increased from 0 wt% to 1.5 wt%. Besides that, incorporation of nanosilica from RHA into cement formulation resulted in reduction of cement porosity up to 18 % pore volume. Overall, the results showed that the incorporation of nanosilica from RHA improved the oil well cement compressive strength and oil well cement porosity. In conclusion, green nanosilica from RHA can be a potential candidate to replace the commercial nanosilica to enhance the oil well cement properties as well as to prevent the migration of undesirable fluid which can lead to major blowout.


ICIPEG 2014 ◽  
2015 ◽  
pp. 121-128 ◽  
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Muhammad Khan Memon ◽  
Shuaib Ahmed Kalwar ◽  
Sandeep Kumar

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jianjian Song ◽  
Mingbiao Xu ◽  
Weihong Liu ◽  
Xiaoliang Wang ◽  
Yumeng Wu

The brittleness and the poor resistance to external load of oil well cement impede the development of oil and gas wells. To overcome these deficiencies, latex powder or rubber and their hybrid combinations were used to modify the oil well cement. The conventional properties, mechanical properties, and scanning electron microscopy (SEM) images of the modified cement were analyzed. In comparison with latex powder-incorporated cement and rubber-incorporated cement, a significant improvement of fluid loss, flexural strength, impact strength, and elasticity of the cement slurry was observed when using the hybrid combinations of 3 wt.% latex powder and 2 wt.% rubber, although this synergistic effect was not remarkable on the compressive strength and the thickening time. These evidences arose from the synergism between latex powder and rubber leading to the formation of a three-dimensional network structure and a flexible structure which subsequently improved the elasticity and toughness of cement stone. The improved elastic matrix has a buffering effect on external impact when the cement stone is subjected to an external load.


Sign in / Sign up

Export Citation Format

Share Document