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Deformation mechanism of horizontal shale gas well production casing and its engineering solution: A case study on the Huangjinba Block of the Zhaotong National Shale Gas Demonstration Zone

Fig. 5. Three-dimensional imaging interpretation of multiple bending deformation of casing in Well H1-2.

It is shown that severe casing deformation tends to occur where structural fractures are developed. Besides, casing deformation is mainly in the form of “S”-shape bending vertically. The severely deformed casing is also characterized by obviously transverse shear deformation caused by the high-angle sliding compression of rocks. Therefore, some suggestions

Current research into the use of supercritical CO2 technology in shale gas exploitation

Fig. 3. Surface comparison of shale before and after ScCO2 fluid treatment (10 MPa, 50 °C) [53].

The research findings indicate that ScCO2 fluid replacement can be used to increase gas production and seal up greenhouse gases as an effective, clean and safe method of shale gas exploitation. It is particularly effective for promoting the desorption of CH4 in shale reservoirs that have developed fine neck-wide body

Data on shale-water based drilling fluid interaction for drilling operation

Data on shale-water based drilling fluid interaction for drilling operation

The dispersion test was conducted, and it involves exposing a weighted quantity of sized shale to the formulated mud in roller-oven. This test is used to design fluids and screen the effectiveness of inhibitor additives to maintain the integrity of the cuttings and minimize the interaction of fluids with the

Introduction to the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoirs

Fig 5 Introduction to the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoirs

And three concepts were proposed, i.e., shale gas fracture network, ideal fracture network and appropriate-stimulation degree of fracture network. The study results indicate that, at the end of reservoir development, target zones can be classified into three types (i.e., relatively appropriate stimulation zone, transitional stimulation zone, and uncompleted stimulation zone)

Geological characteristics, main challenges and future prospect of shale gas

Fig. 2. Distribution diagram for onshore shale gas fields in the US [3].

It includes non-marine shale gas potential, core technology and equipment for resource deep than 3500 m, complex surface “factory mode” production, human geography and other non-technical factors. (4) Process economic evaluation under the conditions of government financial subsidies. China's shale gas project FIRR is about 8.0%–9.0%. Considering the global shale

Shale high pressure isothermal adsorption curve and the production dynamic experiments of gas well

Fig. 2. Instrument for modeling the shale gas development characteristics.

The study results show that the isothermal adsorption law of the shale reservoir under high pressure was different from the conventional low pressure. The high pressure isothermal adsorption curve had the maximum value in excess adsorption with pressure change, and the corresponding pressure was the critical desorption pressure. The high

Molecular simulation of shale gas adsorption in organic-matter nanopore

Fig. 2. Configuration of CH4 and CO2 adsorbed by organic pore (burial depth 4 km). (a) Initial configuration of CH4 adsorbed (b) Initial configuration of CO2 adsorbed; (c) Initial configuration of CH4/CO2 adsorbed;

The results indicated that the adsorptions of CH4 and CO2 were physical and the optimal storage depth was 2 km; The mixed adsorption data showed the rationality of exploit shale gas by injecting CO2 to exchange CH4, and the optimal burial depth was 4 km; The relative density of CH4

Enhancing the rheological properties and shale inhibition behavior of water-based mud using nanosilica, multi-walled carbon nanotube, and graphene nanoplatelet

Figure 2. (a) API filtrate volume tester, and (b) HPHT filtrate volume tester.

Abstract Five different drilling mud systems namely potassium chloride (KCl) as a basic mud, KCl/partial hydrolytic polyacrylamide (PHPA), KCl/graphene nanoplatelet (GNP), KCl/nanosilica and KCl/multi-walled carbon nano tube (MWCNT) were prepared and investigated for enhancement of rheological properties and shale inhibition. Nanoparticles were characterized in drilling mud using transmission electron microscope (TEM)

Three-dimensional characterization of micro-fractures in shale reservoir rocks

Fractures are crucial for unconventional hydrocarbon exploitation, but it is difficult to accurately observe the 3D spatial distribution characteristics of fractures. Microtomography (micro-CT) technology makes it possible to observe the 3D structures of fractures at micro-scale.

Therefore, the independently-developed CTSTA program is adopted to quantitatively describe the micro-fractures inside rock core, including fracture dimension, extension direction and extension scale. Meanwhile, this study summarizes the classification characteristics of fractures and their anisotropy. On this basis, the fractal dimensions of fractures can also be extracted. Previous studies show that

Volume fracturing of deep shale gas horizontal wells

Fig. 1. Comparison between screw perforation and planar perforation.

In addition to planar perforation, multi-scale fracturing, full-scale fracture filling, and control over extension of high-angle natural fractures, some supporting techniques are proposed, including multi-stage alternate injection (of acid fluid, slick water and gel) and the mixed- and small-grained proppant to be injected with variable viscosity and displacement. These techniques

Sustainability of UK shale gas in comparison with other electricity options: Current situation and future scenarios

this paper integrates for the first time environmental, economic and social aspects of shale gas to evaluate its overall sustainability

Abstract Many countries are considering exploitation of shale gas but its overall sustainability is currently unclear. Previous studies focused mainly on environmental aspects of shale gas, largely in the US, with scant information on socio-economic aspects. To address this knowledge gap, this paper integrates for the first time environmental, economic and

Anti-channeling cementing technology for long horizontal sections of shale gas wells

Fig. 1. Diagram of designed and actual well trajectories of Well W204H4-6.

It is indicated that the near-bit three-centralizer drifting BHA used for casing stiffness simulation can decrease the casing running difficulty in the long horizontal section of a shale gas well and increase the time efficiency and safety of casing running; that the flushing efficiency of high-efficiency oil flushing spacer fluid

Removal of organic compounds from shale gas flowback water

Fig. 1. Fractions of TOC (A) and molecular composition of LMW acid (B) and LMW neutral (C) fractions of the shale gas flowback water.

Abstract Ozonation, sorption to granular activated carbon and aerobic degradation were compared as potential treatment methods for removal of dissolved organic carbon (DOC) fractions and selected organic compounds from shale gas flowback water after pre-treatment in dissolved air flotation unit. Flowback water was characterised by high chemical oxygen demand and DOC.

Oil and gas wells and their integrity: Implications for shale and unconventional resource exploitation

Figure 1. Schematic diagram of typical well design, showing (A): structure of an exploration well; and (B): a production well. Depths to which different casings are used vary according to geology and pressure regime of drill site. Well diameter exaggerated to show sections more clearly.

The datasets vary considerably in terms of the number of wells examined, their age and their designs. Therefore the percentage of wells that have had some form of well barrier or integrity failure is highly variable (1.9%–75%). Of the 8030 wells targeting the Marcellus shale inspected in Pennsylvania between 2005