Experimental study of a degradable polymer drilling fluid system for coalbed methane well

Lyu, Shuaifeng; Wang, Shengwei; Chen, Xiaojun; Shah, Saurabh; Li, Rui; Xiao, Yuhang; Dong, Qingxiang; Yin, Gu

doi:10.1016/j.petrol.2019.03.065

Cited by 36 publications

(22 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some researchers studied both of pores and fractures in coals. They characterized such complex natural pores and fractures by many experimental, numerical and analytical methods, including X-ray micro-computed tomography (micro-CT) (Ju et al, 2018;Oleszko et al, 2015;Shah et al, 2017a;Zhou et al, 2018), thin section (Lyu et al, 2019),…”

Section: Introductionmentioning

confidence: 99%

“…Some researchers studied both thepores and fractures in coals. They characterized such complex natural pores and fractures by many experimental, numerical and analytical methods, including X‐ray micro‐computed tomography (micro‐CT) (Ju et al., 2018; Oleszko et al., 2015; Shah, Crawshaw, & Boek, 2017; Zhou et al., 2018), thin section (Lyu et al., 2019), nuclear magnetic resonance (NMR) (Sun et al., 2017), scanning electron microscope (SEM), focused ion beam scanning electron microscopy (FIB‐SEM) (Nie et al., 2015), fractal geometry methods (Cai et al., 2016; Chen & Yao, 2017; Jin et al., 2019; Pandey & Harpalani, 2018), acoustic emission and ultrasonic techniques (Kong et al., 2017; Zhang & Li, 2017), digital drilling imaging technology (Jin et al., 2015; Xie et al., 2015), 2D particle flow code (PFC2D) (Z. Lu et al., 2019; T. Wang et al., 2014, 2017), the discrete element method (Han et al., 2012; McLennan et al., 2010; Shimizu et al., 2011), finite element method, and boundary element method (Hossain & Rahman, 2008) from fracture to matrix, from 2D to 3D, from real scanning to reconstructed realization, and from static to dynamic. For porous media without microfractures, such as sandstone, due to the high self‐similarity of the pores, the fractal theory has been applied well in structure characterization (Chen & Yao, 2017; Chen et al., 2017).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microstructure Analysis on the Fracture Network in High‐Rank Coals

Lyu

Chen

Li³

et al. 2021

Earth and Space Science

Self Cite

View full text Add to dashboard Cite

Microfractures in the coal matrix have complex spatial structure because of the joint effects of coalification and tectonism. The accurate modeling and characterization of microfractures directly affect mechanism analysis of coal rock fracturing and mining. In this study, taking the high-rank coal in the north of Qinshui Basin, structural characteristics of microfracture in intact and tectonic coals were analyzed systematically using 2D thin section, 3D micro-CT modeling and mercury intrusion based on digital image analysis and fractal theory. Result indicates that response sensitivity of fractal parameters obtained from different methods to microfractures from two types of coal structures is different greatly. Single fractal dimension (Df) in tectonic coal is higher than that of intact coal. Specially, for 2D thin sections, the indicative effect on the Df of manually-corrected images is better than that of automaticallyextracted and linear ones. Df has a positive correlation with the pixel-based microfracture porosity, as well as generalized fractal parameters. Moreover, microfracture permeability based on the Cubic-Law increases with the increase of Df. For 3D micro-CT modeling, the classical Watershed algorithm cannot segment the spatial microfracture network, which however can be segmented and characterized by the self-developed FracSC3D program. Spatial microstructural parameters including volume, surface and length at three-axis directions meet bi-fractal characteristics.Specially, for 2D micro-CT slices, with the increase of porosity, the multifractal spectrum width Δα also increased.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microstructure Analysis on the Fracture Network in High‐Rank Coals

Lyu

Chen

Li³

et al. 2021

Earth and Space Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…5,6 In recent years, more and more attentions have been paid to the study of efficient plugging materials as the continuous development of drilling plugging technology of underground gas drainage in coal mines. [7][8][9][10] Polyvinyl alcohol (PVA) is widely used in the fields of biomedicine, 11,12 art cleaning, 13 food packaging 14 and plugging materials, 15 because of its advantages of good water solubility, oil and solvent resistance, low price, and excellent gas barrier properties. [16][17][18] In previous studies, many researchers focused on the preparation of gel plugging materials through PVA.…”

Section: Introductionmentioning

confidence: 99%

Study on the mechanism and performance of polymer gels byTEandPVAchemical cross‐linking

Zhou

Chu

Fan

et al. 2021

J of Applied Polymer Sci

View full text Add to dashboard Cite

Polymer gels are widely used as drilling plugging materials. In this paper, titanium bis(triethanolamine)diisopropoxide (TE) and polyvinyl alcohol (PVA) solution were chemically cross-linked to obtain a gel material. It shows that the OH on the PVA molecular chain are chemically cross-linked with the Ti ion in TE crosslinking agent through complexation reaction, and the crosslinked segment can inhibit the chain motion, resulting in a stable "crab structure" gel configuration. The gel materials synthesized under this configuration were characterized and analyzed by SEM, TG-DSC, GPC, and contact angle measurement. It was demonstrated that the gel performance is optimal when the concentration of TE crosslinking agent is 2.2 wt%, considering the gel strength and gelation time. In addition, the simulated plugging experiment of the gel showed that the service life of the gel was about 72 days, and the sealing performance and tensile recovery performance were significantly improved compared with the previous ones, which would provide a new perspective for the novel plugging materials.

show abstract

“…The adaptability of well pattern arrangement should be considered first and the adaptability between well pattern and coal reservoir is conducive to the rapid realization of interwell interference between wells and expand the range of depressurization (Day et al., 2008; Ely et al., 1990; Feng, 2008). Compared with conventional reservoirs, coal have a unique cleat system, and the density and continuity of cleats are key factors in controlling the permeability of coal reservoirs (Liu et al., 2018a; Lyu et al., 2019; Pan et al., 2010; Shi et al., 2019; Zhao et al., 2016). The researches show that the reservoir with a higher density and better continuity of cleats has greater permeability (Handin et al., 1963; Huang et al., 2018).…”

Section: Introductionmentioning

confidence: 99%

Analysis of hydraulic fracture behavior and well pattern optimization in anisotropic coal reservoirs

Liu

Tang

Hou³

et al. 2020

Energy Exploration & Exploitation

View full text Add to dashboard Cite

Macrolithotypes control the pore-fracture distribution heterogeneity in coal, which impacts stimulation via hydrofracturing and coalbed methane (CBM) production in the reservoir. Here, the hydraulic fracture was evaluated using the microseismic signal behavior for each macrolithotype with microfracture imaging technology, and the impact of the macrolithotype on hydraulic fracture initiation and propagation was investigated systematically. The result showed that the propagation types of hydraulic fractures are controlled by the macrolithotype. Due to the well-developed natural fracture network, the fracture in the bright coal is more likely to form the “complex fracture network”, and the “simple” case often happens in the dull coal. The hydraulic fracture differences are likely to impact the permeability pathways and the well productivity appears to vary when developing different coal macrolithtypes. Thus, considering the difference of hydraulic fracture and permeability, the CBM productivity characteristics controlled by coal petrology were simulated by numerical simulation software, and the rationality of well pattern optimization factors for each coal macrolithotype was demonstrated. The results showed the square well pattern is more suitable for dull coal and semi-dull coal with undeveloped natural fractures, while diamond and rectangular well pattern is more suitable for semi-bright coal and bright coal with more developed natural fractures and more complex fracturing fracture network; the optimum wells spacing of bright coal and semi-bright coal is 300 m and 250 m, while that of semi-dull coal and dull coal is just 200 m.

show abstract

Experimental study of a degradable polymer drilling fluid system for coalbed methane well

Cited by 36 publications

References 37 publications

Microstructure Analysis on the Fracture Network in High‐Rank Coals

Microstructure Analysis on the Fracture Network in High‐Rank Coals

Study on the mechanism and performance of polymer gels byTEandPVAchemical cross‐linking

Analysis of hydraulic fracture behavior and well pattern optimization in anisotropic coal reservoirs

Contact Info

Product

Resources

About