scholarly journals Application of Microemulsion Systems in the Formulation of Biodegradable Pre-Flush Fluid for Primary Cementing

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4683
Author(s):  
Elayne A. Araújo ◽  
Thaine T. Caminha ◽  
Evanice M. Paiva ◽  
Raphael R. Silva ◽  
Júlio Cézar O. Freitas ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Xrd Analysis ◽  
Oil Well ◽  
Cement Slurry ◽  
Removal Time ◽  
Primary Cementing ◽  
Flush Fluid ◽  
Cake Removal

Oil well cleanup fluids (pre-flushes) are intermediate fluids pumped ahead of the cement slurry; they are able to clean the well walls by removing the filter cake formed by the drilling fluid, and leave the surface water-wet. This work’s main objective was to use biodegradable microemulsion systems as cleanup fluids in order to reduce the environmental impact. Three microemulsion systems were formulated, each composed of an oil phase, a surfactant and three different aqueous phases: glycerol, glycerol:water (mass ratio 1:1), and fresh water. The results show that all microemulsion systems were effective with 100% filter cake removal, with a removal time of less than 60 s. The wettability test and fluid compatibility analyses exhibited advantageous performances, without phase separation, variations in viscosity, gelation, or flocculation. The compressive strength and X-ray diffractometry (XRD) analysis showed the influence of the glycerol on the cement slurry properties, with the compressive strength resistance ranging from 8.0 to 10.7 MPa, and resulted in the formation of portlandite.

Carbon Dioxide Corrosion and Corrosion Prevention of Oil Well Cement Paste Matrix in Deep Wells

2014 ◽  
Vol 692 ◽  
pp. 433-438 ◽  
Author(s):  
Jing Fu Zhang ◽  
Jin Long Yang ◽  
Kai Liu ◽  
Bo Wang ◽  
Rui Xue Hou
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Cement Paste ◽  
Oil Wells ◽  
Oil Well ◽  
Cement Slurry ◽  
Corrosion Prevention ◽  
Oil Well Cement ◽  
Oil Well Cement Paste ◽  
Well Cement

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.

Well Clean-Up Using a Combined Thermochemical/Chelating Agent Fluids

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Chelating Agent ◽  
Drilling Fluids ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Different Types ◽  
Cake Removal

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.

scholarly journals Utilization of metakaolin-based geopolymer as a mud-cake solidification agent to enhance the bonding strength of oil well cement–formation interface

2020 ◽  
Vol 7 (2) ◽  
pp. 191230
Author(s):  
Yuhuan Bu ◽  
Rui Ma ◽  
Jiapei Du ◽  
Shenglai Guo ◽  
Huajie Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Bonding Strength ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Research Work ◽  
Drilling Fluids ◽  
Oil Well ◽  
Mud Cake ◽  
Calculation Methodology ◽  
Zonal Isolation

This research work designed a novel mud-cake solidification method to improve the zonal isolation of oil and gas wells. The calculation methodology of mud-cake compressive strength was proposed. The optimal formula of activator and solid precursors, the proper activating time and the best activator concentration were determined by the compressive strength test. The effects of solid precursors on the properties of drilling fluid were evaluated. Test results show that the respective percentage of bentonite, metakaolin, slag and activator is 1 : 1 : 0.3 : 0.8, as well as the optimum ratio of Na 2 SiO 3 /NaOH is 40 : 1. The optimum concentration of activator is 0.21 and the activating time should be more than 10 min. The solid precursors did not show any bad influence on the rheological property of drilling fluids. Even though the compressive strength decreased when the solid precursors blended with barite, the strength values can still achieve 8 MPa. The reaction of metakaolin and activator formed cross-link structure in the mud-cake matrix, which enhanced the connection of the loose bentonite particles, lead to the significant enhancement of shear bonding strength and hydraulic bonding strength. This mud-cake solidification method provides a new approach to improve the quality of zonal isolation.

Evaluation of Constitutive Equation for Stress in Solids in Porous Media Composed of Bridging Agents Used in Drilling Fluids

2012 ◽  
Vol 727-728 ◽  
pp. 1878-1883 ◽  
Author(s):  
Bruno Arantes Moreira ◽  
Flávia Cristina Assis Silva ◽  
Larissa dos Santos Sousa ◽  
Fábio de Oliveira Arouca ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Porous Media ◽  
Constitutive Equation ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Oil Well ◽  
Well Drilling ◽  
Drilling Operations ◽  
The Stability

During oil well drilling processes in reservoir-rocks, the drilling fluid invades the formation, forming a layer of particles called filter cake. The formation of a thin filter cake and low permeability helps to control the drilling operation, ensuring the stability of the well and reducing the fluid loss of the liquid phase in the interior of the rocks. The empirical determination of the constitutive equation for the stress in solids is essential to evaluate the filtration and filter cake formation in drilling operations, enabling the operation simulation. In this context, this study aims to evaluate the relationship between the porosity and stress in solids of porous media composed of bridging agents used in drilling fluids. The concentration distribution in sediments was determined using a non-destructive technique based on the measure of attenuated gamma rays. The procedure employed in this study avoids the use of compression-permeability cell for the sediment characterization.

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
Keyword(s):  
Compressive Strength ◽  
Oil And Gas ◽  
Free Water ◽  
American Petroleum Institute ◽  
Oil Well ◽  
Cement Slurry ◽  
X Ray ◽  
Gas Drilling ◽  
Drilling Operations ◽  
Well Cement

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.

scholarly journals The Effect of Weighting Materials on Oil-Well Cement Properties While Drilling Deep Wells

2019 ◽  
Vol 11 (23) ◽  
pp. 6776 ◽  
Author(s):  
Abdulmalek Ahmed ◽  
Ahmed Abdulhamid Mahmoud ◽  
Salaheldin Elkatatny ◽  
Weiqing Chen
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Density Variation ◽  
Cement Matrix ◽  
Oil Well ◽  
Cement Slurry ◽  
Deep Wells ◽  
Porosity And Permeability ◽  
Maximum Particle ◽  
Well Cement

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.

scholarly journals Application of cellulose-based polymers in oil well cementing

2019 ◽  
Vol 10 (2) ◽  
pp. 319-325
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Khalil Rehman Memon ◽  
Javed Khan
Keyword(s):  
Compressive Strength ◽  
Free Water ◽  
Hydroxyethyl Cellulose ◽  
Petroleum Engineering ◽  
Fluid Loss ◽  
Oil Well ◽  
Operational Cost ◽  
Cement Slurry ◽  
Multifunctional Additive ◽  
Water Separation

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.

scholarly journals A simple NMR methodology for evaluating filter cake properties and drilling fluid-induced formation damage

2019 ◽  
Vol 10 (4) ◽  
pp. 1643-1655 ◽  
Author(s):  
Abdulrauf R. Adebayo ◽  
Badr S. Bageri
Keyword(s):  
Filter Cake ◽  
Rock Sample ◽  
Drilling Fluid ◽  
Material Balance ◽  
Cumulative Distribution ◽  
Fluid Loss ◽  
Secondary Damage ◽  
Volume Porosity ◽  
Filtration Loss ◽  
Cake Removal

Abstract An efficient drilling fluid will form a filter cake that will minimize the drilling fluid invasion into any drilled formation. Drilling fluid must therefore be adequately evaluated in the laboratory prior to field trial. Filter cake properties such as thickness, porosity, permeability, and pore structure are frequently evaluated using several techniques such as CT scan, SEM, and XRF. However, each of these techniques can evaluate only one or two filter cake properties. This paper presents a simple but novel NMR technique to evaluate filter cake properties such as thickness, pore volume, porosity, and possibly permeability. Furthermore, the amount and particle size distribution of solids that invaded a given rock sample can be obtained using the same technique. The full procedure was tested and verified using four identical rock samples. Drilling fluid invasion and filter cake deposition experiments were conducted on each of the samples, using the same drilling fluid but four different concentrations of fluid loss additive. NMR T2 relaxation measurements were taken at three different stages of each rock sample: before filter cake deposition; after fluid invasion and filter cake deposition; and after filter cake removal. A material balance analysis of the probability density function and cumulative distribution function of the measured T2 profile at the different stages of each sample yielded multiple filtration loss properties of the filter cake. The results obtained showed high accuracy of the NMR versus the current techniques. Moreover, this current method evaluated the majority of the filter cake properties at the same time and in situ hence eliminated the need of using multi-procedures that disturb the sample state. Finally, the presented method can also be used to evaluate secondary damage associated with filter cake removal process.

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