Screening of Lost Circulation Materials for Geothermal Applications: Experimental Study at High Temperature

2021 ◽  
pp. 1-16
Author(s):  
Cesar Vivas ◽  
Saeed Salehi

Abstract This study presents a laboratory experimental research to determine the characteristics of lost circulation materials (LCM) capable of addressing thermal degradation, providing bridging, and sealing in geothermal conditions. Eleven different materials were tested; Walnut Fine, Walnut Medium, Sawdust, Altavert, Graphite Blend, Bentonite Chips, Micronized Cellulose (MICRO-C), Magma Fiber Fine, diatomaceous earth/amorphous silica powder (DEASP), Cotton Seed Hulls, and a Calcium Carbonate Blend. The filtration and sealing pressure of the LCMs were measured with HPHT equipment up to 149°C (300°F). Besides, the particle size distribution (PSD) of fine granular materials was measured. The results show that the performance of some LCM materials commonly used in geothermal operations is affected by high temperature. Characteristics such as shape and size made some materials more prone to thermal degradation. Also, it was found that the PSD of LCMs is a key factor in the effectiveness of bridging and sealing fractures. The results suggest that granular materials with a wide particle size distribution PSD are suitable for geothermal applications.

2022 ◽  
pp. 1-15
Author(s):  
Lu Lee ◽  
Arash Dahi Taleghani

Summary Lost circulation materials (LCMs) are essential to combat fluid loss while drilling and may put the whole operation at risk if a proper LCM design is not used. The focus of this research is understanding the function of LCMs in sealing fractures to reduce fluid loss. One important consideration in the success of fracture sealing is the particle-size distribution (PSD) of LCMs. Various studies have suggested different guidelines for obtaining the best size distribution of LCMs for effective fracture sealing based on limited laboratory experiments or field observations. Hence, there is a need for sophisticated numerical methods to improve the LCM design by providing some predictive capabilities. In this study, computational fluid dynamics (CFD) and discrete element methods (DEM) numerical simulations are coupled to investigate the influence of PSD of granular LCMs on fracture sealing. Dimensionless variables were introduced to compare cases with different PSDs. We validated the CFD-DEM model in reproducing specific laboratory observations of fracture-sealing experiments within the model boundary parameters. Our simulations suggested that a bimodally distributed blend would be the most effective design in comparison to other PSDs tested here.


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 640
Author(s):  
Junjie Tang ◽  
Yuan Sun ◽  
Chunwei Zhang ◽  
Long Wang ◽  
Yizhou Zhou ◽  
...  

The preparation of rhenium powder by a hydrogen reduction of ammonium perrhenate is the only industrial production method. However, due to the uneven particle size distribution and large particle size of rhenium powder, it is difficult to prepare high-density rhenium ingot. Moreover, the existing process requires a secondary high-temperature reduction and the deoxidization process is complex and requires a high-temperature resistance of the equipment. Attempting to tackle the difficulties, this paper described a novel process to improve the particle size distribution uniformity and reduce the particle size of rhenium powder, aiming to produce a high-density rhenium ingot, and ammonium perrhenate is completely reduced by hydrogen at a low temperature. When the particle size of the rhenium powder was 19.74 µm, the density of the pressed rhenium ingot was 20.106 g/cm3, which was close to the theoretical density of rhenium. In addition, the hydrogen reduction mechanism of ammonium perrhenate was investigated in this paper. The results showed that the disproportionation of ReO3 decreased the rate of the reduction reaction, and the XRD and XPS patterns showed that the increase in the reduction temperature was conducive to increasing the reduction reaction rate and reducing the influence of disproportionation on the reduction process. At the same reduction temperature, reducing the particle sizes of ammonium perrhenate was conducive to increasing the hydrogen reduction rate and reducing the influence of the disproportionation.


2016 ◽  
Vol 35 ◽  
pp. 836-850 ◽  
Author(s):  
Omid Razavi ◽  
Ali Karimi Vajargah ◽  
Eric van Oort ◽  
Munir Aldin ◽  
Sudarshan Govindarajan

2020 ◽  
Vol 10 (5) ◽  
pp. 657-662
Author(s):  
Gang Wang ◽  
Honghai Fan ◽  
Guancheng Jiang ◽  
Wanjun Li ◽  
Yu Ye ◽  
...  

In this paper, the cross-linked micro-gel polymer between acrylamide (AM) and N, N-Methylenebisacrylamide (MBA) was synthesized by dispersion polymerization. The initiator and crosslinking agent concentration were used to control the particle size of micro-gel polymer. The filtration property and mechanism of micro-gel were investigated comprehensively. The characteristics of micro-gel were checked by means of Fourier transform infrared spectroscopy, thermogravimetry, transmission electron microscopy, and particle size distribution, respectively. The results indicated that the cross-linked micro-gel polymer exhibited several outstanding merits, such as thermal stability (up to 200 °C), filtration control and rheological property. Microstructure analysis and particle size distribution examinations showed that the scale of micro-gel polymer was micro, which is in accord with design. Rheological tests demonstrated that the nonlinear structure of micro-gel polymer showed less impact on the apparent viscosity. The anti-high temperature property of micro-gel polymer was better than poly anioniccellulose (PAC) and asphalt widely applied in drilling fluid for anti-high temperature fluid-loss additive. As a result, the cross-linked micro-gel polymer had great potential to be applied in high temperature water-based mud.


2021 ◽  
Vol 377 ◽  
pp. 666-675
Author(s):  
Ragunanth Venkatesh ◽  
Miha Brojan ◽  
Igor Emri ◽  
Arkady Voloshin ◽  
Edvard Govekar

2007 ◽  
Vol 14 (03) ◽  
pp. 445-449 ◽  
Author(s):  
JIE-GUANG SONG ◽  
LIAN-MENG ZHANG ◽  
JUN-GUO LI ◽  
JIAN-RONG SONG

Zirconium diboride is widely applied to high-temperature materials, but it is easily oxidized at high temperature. To increase the oxidation resistance of zirconium diboride at high temperature, the A 1( OH )3– Y ( OH )3 is coated on the ZrB 2 surface to prepare A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles. In this paper, the effect of coating content on the properties of A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles is investigated. It is analyzed that the particle size and particle size distribution of A 1( OH )3– Y ( OH )3/ ZrB 2 composite particles is increased with the coating content. The dispersion of ZrB 2 particles is largely increased with the coating content of 0%–20%; the dispersion of ZrB 2 particles is similar when the coating content is from 20% to 30%. The oxidation resistance ratio of the ZrB 2 particles with 30% coating content is the best than that of other conditions—it is about three times more than that of the original ZrB 2 particles.


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