scholarly journals A Brief Review of Gas Migration in Oilwell Cement Slurries

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2369
Author(s):  
Chengcheng Tao ◽  
Eilis Rosenbaum ◽  
Barbara G. Kutchko ◽  
Mehrdad Massoudi
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Oil And Gas ◽  
Free Water ◽  
Gel Strength ◽  
Fluid Loss ◽  
Gas Migration ◽  
Cement Slurry ◽  
Wellbore Pressure ◽  
Lower Fluid

Gas migration in oil and gas wells is defined as gases and/or fluids from adjacent formations invading a freshly cemented annulus. During well completions, gas and/or fluids can migrate to zones with lower pressure or even to the surface. Static gel strength (SGS), related to the yield stress of the cement, is a widely accepted measurement used to predict and minimize gas migration. In this review article, we look at the mechanisms and some possible solutions to gas migration during oil and gas well cementing. The use of static gel strength (SGS) and experimental measurements for SGS and wellbore pressure reduction are discussed. Rheological properties, including the yield stress and the viscosity of cement slurries, are also briefly discussed. Understanding the rheological properties of cement is complex since its material properties depend on cement type, as well as the shape and size distribution of cement particles. From this brief review, it is evident that in order to reduce free water and settling of the cement particles, to lower fluid loss, and to develop compressive strength in the early stages of cementing, an optimal cement slurry design is needed. The SGS test is a standard method used in estimating the free water in the well and could be a reference for gas migration reduction for oilwell cement slurries.

scholarly journals Analyzing Cement Rheological Properties Using Different Additive Schemes at High Pressure and High Temperature Conditions

2020 ◽  
Vol 39 (3) ◽  
pp. 466-474
Author(s):  
Khalil Rehman Memon ◽  
Aftab Ahmed Mahesar ◽  
Shahzad Ali Baladi ◽  
Muhannad Talib Sukar
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Rheological Properties ◽  
Silica Fume ◽  
Gel Strength ◽  
Water Quantity ◽  
Fluid Loss ◽  
Cement Slurry ◽  
Three Samples ◽  
Loss Control

The experimental study was conducted on rheological properties in laboratory to measure the integrity of cement slurry. Three samples were used and analyzed at different parameters to check the elasticity of cement slurry. Additives with various concentrations, i.e. silica fume % BWOC (Present by Weight on Cement) (15, 17, 19 and 21), dispersant % Wt (Percent Weight) (0.21, 0.26 and 0.31) and additional 1; % Wt of fluid losscontrol were used to improve the performance of the cement slurry at the temperature of 123oC. The results have shown that increase in the concentration of dispersants that have caused to decrease in the Plastic Viscosity (PV), Yield Point (YP) and GS (Gel Strength). The rheological properties of cement were improved with the addition of fluid loss control additive in 21 % BWOC (Present by Weight on Cement) silica fume increase the water quantity in cement slurry that improve its durability and to reduce the strength retrogression in High Temperature High Pressure (HTHP) environment. Results were achieved through HTHP OFITE Viscometer (Model 1100).

scholarly journals Badania procesu żelowania zaczynów cementowych przeznaczonych do uszczelniania otworów przewiercających płytkie poziomy gazonośne

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (4) ◽  
pp. 235-243
Author(s):  
Marcin Rzepka ◽  
◽  
Miłosz Kędzierski ◽  
Keyword(s):  
Hydrostatic Pressure ◽  
Oil And Gas ◽  
Gel Strength ◽  
Gas Migration ◽  
Annular Space ◽  
Cement Slurry ◽  
National Research Institute ◽  
Shallow Gas ◽  
High Molecular Weight Polymer ◽  
Research Institute

The article presents issues related to the sealing slurry technology concerning gelling processes (i.e., static built-up of gel strength of cement slurries). Based on research conducted around the world, it can be concluded that the rate of gelling of the cement slurry has an important role in the process of preventing possible gas exhalations from the annular space. After the cement slurry is pumped into the borehole (especially in zones with shallow gas horizons), the so-called migration (exhalation) of the formation medium (i.e. uncontrolled outflow of e.g. gas from the annular space) may occur. The most important caused of gas migration from the shallow horizons after casings cementation are the inability to maintain a certain overpressure by the column of the binding cement slurry and too long binding of the cement slurry after pumping into the borehole. The initially liquid cement slurry, when pumped out of the casing, acts as a liquid, creating a certain hydrostatic pressure on the deposit. e.g. gas. However, after some time, the period of building the static gel strength (SGS) starts until the cement sets. The SGS building process, i.e. gelling of the cement slurry, reduces the ability to transmit hydrostatic pressure to the reservoir. The Oil and Gas Institute – National Research Institute has tested a number of cement slurry formulations characterized by different gelling and bonding times. Slurries were made on the basis of three typed of latex with the symbols L1, L2, L3, two types of water glass with symbols S1, S2, amorphous silica with the symbol CB, nano-components based on n-SiO2 and n-Al2O3 with the symbols NS and NA as well as high-molecular weight polymer with the symbol GS. Different amounts of setting accelerator were used with the tested slurries. Tests were carried out for eighteen cement recipes, which made it possible to select the optimal compositions of slurries with short gelling and setting times. The samples containing one of the types of latex in the appropriate concentration, the GS polymer, as well as those containing n-SiO2 and n-Al2O3, showed a very advantageous course of the gelation plot (static build-up of gel strength). Their TT transition times, reflecting the course of gelation, ranged from several to several tens of minutes (which is a proof of high ability to prevent gas migration from shallow gas accumulations). The cement slurries developed at the Oil and Gas Institute – National Research Institute, due to their good technological parameters, could be used in the process of cementing casing strings.

Improvement and Control of Cement Slurry Formulation Resistant to the Critical Conditions HPHT

2015 ◽  
Vol 1105 ◽  
pp. 339-345
Author(s):  
Soumia Bechar ◽  
Djamal Zerrouki
Keyword(s):  
High Temperature ◽  
Oil And Gas ◽  
Aqueous Suspension ◽  
Free Water ◽  
Critical Conditions ◽  
Fluid Loss ◽  
Cement Slurry ◽  
Sodium Lignosulfonate ◽  
And Control ◽  
Styrene Butadiene

The ambition of the world oil industry is currently directed toward the deepest traps of oil and gas, despite the very high temperatures. The objective of this study is to improve and control a conventional formulation of cement slurry that meets the critical conditions during the cementing of 7" liner on high pressure/high temperature (HPHT) gas well at 5570m depth, located at Hassi Berkine in the southern Algeria. Under the influence of high temperature, the characteristics of the cement slurry changed. We carried out several tests on various samples in order to revise the design by using equivalent substitutions of the additives to obtain a better profile. The use of a new, very powerful, synthetic retarder (SR-31L) instead of liquid, modified sodium lignosulfonate (R-15 L) led us to obtain a significant thickening time but decreased the rheological properties as well as fluid loss and free water. We also provided a gas block by introducing latex-styrene-butadiene with a specific stabilizer (LS-1) in combination with a compatible bonding agent (amorphous silica) in aqueous suspension (BA-58L). The study determined one of the best cement slurry designs practicable on different down-hole applications in HPHT wells.

Improving Oil well Cement Slurry Performance Using Hydroxypropylmethylcellulose Polymer

2013 ◽  
Vol 787 ◽  
pp. 222-227 ◽  
Author(s):  
Ghulam Abbas ◽  
Sonny Irawan ◽  
Sandeep Kumar ◽  
Ahmed A.I. Elrayah
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Rheological Properties ◽  
Elevated Temperatures ◽  
Free Water ◽  
Oil Wells ◽  
Fluid Loss ◽  
Cement Slurry ◽  
Multifunctional Additive ◽  
Wide Range

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.

Synthesis and performance of a self crosslinkable acrylate copolymer with high compatibility for an oil well cement modifier

2014 ◽  
Vol 34 (5) ◽  
pp. 405-413
Author(s):  
Xianru He ◽  
Qian Chen ◽  
Chunhui Feng ◽  
Liang Wang ◽  
Hailong Hou
Keyword(s):  
High Performance ◽  
Oil And Gas ◽  
High Strength ◽  
Ammonium Persulfate ◽  
Fluid Loss ◽  
Oil Well ◽  
Cement Slurry ◽  
Oil Well Cement ◽  
Well Cement ◽  
Loss Control

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.

Research and Application of Ultra-High Cementing Slurry

2016 ◽  
Vol 847 ◽  
pp. 485-489
Author(s):  
Xing Cai Zhang ◽  
Xiao Wei Cheng ◽  
Xiao Yang Guo
Keyword(s):  
High Temperature ◽  
Oil And Gas ◽  
Good Effect ◽  
Fluid Loss ◽  
Cement Slurry ◽  
Sedimentation Stability ◽  
Temperature Resistance ◽  
Deep Wells ◽  
High Temperature Resistance ◽  
Shallow Wells

With the exploration of oil and gas in depth, shallow wells already can’t satisfy the requirement, therefore to explore and develop deep reservoirs is necessary. In the case of deep wells the loop temperature of bottom can reach to 150°C-200°C, which put forward a higher requirement for the high temperature resistance property of cement slurry. At present, many problems existed in the most of high temperature cement slurry. For example, high temperature resistance is not well, cement thickening time can’t adjust easily, mega-thermal sedimentation stability is unsatisfactory, and ultra-retarding phenomenon appeared for the top prone. After research indoors, we developed the ultra-high temperature slurry system by means of the investigation on cementing additives and select proper materials from high temperature resistant fluid loss additives, retarders, flowable agent at the same time. This system needs a lots of properties, such as, adjustable slurry thickening time below 200°C, great slurry sedimentation stability, API loss can be controlled at the range of 0-50ml, insensitive to temperature and density, could be used in low-density and conventional density cement etc. This system be used successfully in the well that loop temperature of bottom reaches to 185°C and get a good effect finally.

Enhanced Cement Composition for Preventing Annular Gas Migration

2019 ◽  
Author(s):  
George Kwatia ◽  
Mustafa Al Ramadan ◽  
Saeed Salehi ◽  
Catalin Teodoriu
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Oil Well ◽  
Gas Migration ◽  
Cement Slurry ◽  
Gas Industry ◽  
Well Integrity ◽  
Transit Times ◽  
Well Cement ◽  
Gas Tight

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.

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 Effect of polycarboxylate superplasticizer on fluidity and rheology of cement slurry containing silica fume

2021 ◽  
Vol 237 ◽  
pp. 03008
Author(s):  
Qingen Meng ◽  
Juan He ◽  
Congmi Cheng ◽  
Xiaofen Zhu
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
Plastic Viscosity ◽  
Cement Slurry ◽  
Pseudoplastic Fluid ◽  
Plasticizer Content ◽  
Polycarboxylate Superplasticizer ◽  
Dispersion Degree ◽  
Fluid Characteristic

The effect of polycarboxylate superplasticizer on the fluidity and rheology of cement - silica fume - water paste was investigated. The changes of dispersion degree, yield stress and plastic viscosity of paste with different superplasticizer content were analyzed. The results show that the rheological properties of paste with different superplasticizer content conform to Herschel-Bulkley model. The shear thinning of the slurry is manifested as a typical yielding pseudoplastic fluid characteristic. When the content of superplasticizer is less than 1.0%, the plastic viscosity and yield stress decrease and the fluidity increase with the increase of plasticizer content. When the content of superplasticizer is more than 1.0%, the yield stress decreases slightly and the plastic viscosity increases with the increase of plasticizer content. The fluidity decreases with the increase of yield stress, and there is a good correlation between them.

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.

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