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Retention of Hydraulic Fracturing Water in Shale: The Influence of Anionic Surfactant

Figure 5. The Energy-Dispersive X-Ray (EDX) spectra of (a) BG-2 and (b) KH-2 shales with a corresponding miniature FE-SEM images.

Retention of Hydraulic Fracturing Water in Shale: The Influence of Anionic Surfactant However, the role of some surface active agents like surfactants that are added in the hydraulic fracturing mixture in this issue needs to be understood. In this study, the influence of Internal Olefin Sulfate (IOS), which is an anionic

Mechanisms and Influence of Casing Shear Deformation near the Casing Shoe, Based on MFC Surveys during Multistage Fracturing in Shale Gas Wells in Canada

Figure 1. Geological stratification and well structure.

Mechanisms and Influence of Casing Shear Deformation near the Casing Shoe, Based on MFC Surveys during Multistage Fracturing in Shale Gas Wells in Canada For the purpose of increasing calculation accuracy, the elastoplastic constitutive relations of materials were considered, and the solid-shell elements technique was used. The reduction of the casing’s

Impact of Casing Eccentricity on Cement Sheath

Figure 3. Sketch of a casing–cement–formation system in a horizontal well.

Impact of Casing Eccentricity on Cement Sheath To better understand stress distribution in eccentric cement sheaths, an analytical model is proposed in this paper. By comparing the results of this model with the one’s with centric casing, the impacts of the casing eccentricity on the integrity of the cement sheath is

Pore evolution in hydrocarbon-generation simulation of organic matter-rich muddy shale

Fig. 4. FESEM images of carbonaceous mudstone and the simulated samples at different temperatures.

However, in the high mature-overmature stage, shale porosity decreased with further increase of temperature and pressure. In contrast to micropores, micro-scale capillary pores and megapores in shale constantly decreased as rise of simulation temperature or pressure, indicating that deep-burial reservoirs was not favorable for free-gas storage; but significant increase of

Microstructural imaging and characterization of oil shale before and after pyrolysis

Fig. 13. (A) Porosity of 10 oil shale samples after pyrolysis at 500 °C, (B) – (D). 2-D gray scale images for organic-rich, organic-mixed and organic-lean regions respectively. (E) – (G) 3-D rendered volumes with the pore space visualized in blue.

Abstract The microstructural evaluation of oil shale is challenging which demands the use of several complementary methods. In particular, an improved insight into the pore network structure and connectivity before, during, and after oil shale pyrolysis is critical to understanding hydrocarbon flow behavior and enhancing recovery. In this experimental study, bulk

Mechanism of multi-stage sand filling stimulation in horizontal shale gas well development

Fig. 1. Body-centered cubic and face-centered cubic models of equant spheres.

With consideration to the limitations in the implementation of the mechanical staging technique with bridge plug for shale gas development in the Sichuan–Chongqing area, the technique of multi-stage sand filling stimulation in horizontal wells was proposed to solve the above-mentioned problems. By filling sands in fractures, it is possible to

Strengthening shale wellbore with silica nanoparticles drilling fluid

Fig. 7. SEM images of shale surface (a) nanoparticles within shale and (b) aggregate of nanoparticles plugging a pore throat.

Higher concentration of nanoparticles can induce better plugging effect. However, for the OBDFs, nanoparticles did not show these positive effects like the nano WBDFs, even leaded to some negative effects such as higher filtration and larger Young's-modulus reduction. The main reasons are that the silica nanoparticles can easily disperse in

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

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

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)

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

Adsorption damage and control measures of slick-water fracturing fluid in shale reservoirs

Fig. 1 Experimental integrating shale displacement unit and ultraviolet spectrophotometer.

With the increase of pH value, the adsorption capacity decreased gradually, the adsorption capacity increased first and then decreased with the increase of temperature, and the adsorption capacity was the largest at 45°C. The adsorption patterns of polymers on shale were described by scanning electron microscopy and magnetic resonance imaging.

Shale hydration inhibition characteristics and mechanism of a new amine-based additive in water-based drilling fluids

In this work, shale hydration Inhibition performance of tallow amine ethoxylate as a shale stabilizer in water based drilling fluid, was investigated through these tests: bentonite hydration inhibition test, bentonite sedimentation test, drill cutting recovery test, dynamic linear swelling test, wettability test, isothermal water adsorption test, and zeta potential test.

Some amine functional groups exist in tallow amine ethoxylate structure which are capable of forming hydrogen bonding with surfaces of bentonite particles. This phenomenon decreased the water adsorption on bentonite particles' surfaces which results in reduction of swelling. Tallow amine ethoxylate is also compatible with other common drilling fluid additives. Introduction A

Elastic–Brittle–Plastic Behaviour of Shale Reservoirs and Its Implications on Fracture Permeability Variation: An Analytical Approach

Fig. 1 a Fractures in shale core samples (Gale et al. 2014), b a subvertical calcite-cemented fracture (Soeder 1988), c simplified dual porosity concept for shale

Desorption of gas during production can cause shrinkage of the organic content of the rock. This becomes more important when considering the use of shales for CO2 sequestration purposes, where CO2 adsorption-induced swelling can play an important role. These phenomena lead to changes in the stress state within the rock

Development of a new correlation to determine the static Young’s modulus

Fig. 13 Estimated Young’s modulus value from dynamic one using different correlation, case #2 limestone formation. E new is the static Young’s modulus estimated by the developed correlation, and it gives the best match with the core measured data and the lowest root-mean-square error. a Prediction of static Young’s modulus. b Root-mean-square error

The laboratory values are then used to correlate the dynamic values derived from the logs. Several correlations were introduced in the literature, but those correlations were very specific and when applied to different cases they gave very high errors and were limited to relating the dynamic Young’ modulus with the