In Situ Sample for Hydraulic Fracturing and Laboratory Analysis Dataset in Xishui County，Guizhou Province of China

Gamma-ray spectrometer calibration for field analysis of thorium, uranium and potassium

Canadian Journal of Earth Sciences ◽

10.1139/e70-102 ◽

1970 ◽

Vol 7 (4) ◽

pp. 1093-1098 ◽

Cited By ~ 14

Author(s):

P. G. Killeen ◽

C. M. Carmichael

Keyword(s):

Regression Analysis ◽

Gamma Ray ◽

Laboratory Analysis ◽

In Situ Analysis ◽

Field Analysis ◽

Gamma Ray Spectrometer ◽

Nonlinear Relation ◽

Using Data ◽

Spectrometer Calibration

The calibration of a portable three-channel gamma-ray spectrometer for in situ analysis of thorium, uranium, and potassium is discussed. A method of regression analysis is suggested as the best means of including all of the data available from the calibration stations. Calibration indicates a nonlinear relation between count rates obtained in the field and concentrations in parts per million obtained from laboratory analysis. The range of radioelement content must be taken into consideration and appropriate sets of calibration constants applied. As an example of the method, calibration constants are calculated for a portable gamma-ray spectrometer using data for the Blind River uranium region of Ontario.

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Mercury methylation in paddy soil: source and distribution of mercury species at a Hg mining area, Guizhou Province, China

Biogeosciences ◽

10.5194/bg-13-2429-2016 ◽

2016 ◽

Vol 13 (8) ◽

pp. 2429-2440 ◽

Cited By ~ 34

Author(s):

Lei Zhao ◽

Christopher W. N Anderson ◽

Guangle Qiu ◽

Bo Meng ◽

Dingyong Wang ◽

...

Keyword(s):

Paddy Soil ◽

Surface Soil ◽

Ambient Air ◽

Rice Paddy ◽

Guizhou Province ◽

Mercury Species ◽

Low Concentration ◽

Paddy Water ◽

Hg Mining

Abstract. Rice paddy plantation is the dominant agricultural land use throughout Asia. Rice paddy fields have been identified as important sites for methylmercury (MeHg) production in the terrestrial ecosystem and a primary pathway of MeHg exposure to humans in mercury (Hg) mining areas. We compared the source and distribution of Hg species in different compartments of the rice paddy during a complete rice-growing season at two different typical Hg-contaminated mining sites in Guizhou province, China: an abandoned site with a high Hg concentration in soil but a low concentration in the atmosphere and a current-day artisanal site with a low concentration in soil but a high concentration in the atmosphere. Our results showed that the flux of new Hg to the ecosystem from irrigation and atmospheric deposition was insignificant relative to the pool of old Hg in soil; the dominant source of MeHg to paddy soil is in situ methylation of inorganic Hg (IHg). Elevated MeHg concentrations and the high proportion of Hg as MeHg in paddy water and the surface soil layer at the artisanal site demonstrated active Hg methylation at this site only. We propose that the in situ production of MeHg in paddy water and surface soil is dependent on elevated Hg in the atmosphere and the consequential deposition of new Hg into a low-pH anoxic geochemical system. The absence of depth-dependent variability in the MeHg concentration in soil cores collected from the abandoned Hg mining site, consistent with the low concentration of Hg in the atmosphere and high pH of the paddy water and irrigation water, suggested that net production of MeHg at this site was limited. We propose that the concentration of Hg in ambient air is an indicator for the risk of MeHg accumulation in paddy rice.

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Development of hydraulic fracturing in-situ stress measurement technology and its application

In-Situ Rock Stress ◽

10.1201/9781439833650.ch16 ◽

2006 ◽

pp. 121-126

Author(s):

Q Guo ◽

Q Chen ◽

C Wang

Keyword(s):

Hydraulic Fracturing ◽

Stress Measurement ◽

In Situ Stress ◽

Measurement Technology ◽

In Situ Stress Measurement

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The Application of Hydraulic Fracturing in Storage Projects of Liquefied Petroleum Gas

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.306-308.1509 ◽

2006 ◽

Vol 306-308 ◽

pp. 1509-1514 ◽

Cited By ~ 1

Author(s):

Jing Feng ◽

Qian Sheng ◽

Chao Wen Luo ◽

Jing Zeng

Keyword(s):

Rock Mass ◽

Hydraulic Fracturing ◽

Stress Measurement ◽

Test Procedure ◽

In Situ Stress ◽

Test System ◽

Petroleum Engineering ◽

Liquefied Petroleum Gas

It is very important to study the pristine stress field in Civil, Mining, Petroleum engineering as well as in Geology, Geophysics, and Seismology. There are various methods of determination of in-situ stress in rock mass. However, hydraulic fracturing techniques is the most convenient method to determine and interpret the test results. Based on an hydraulic fracturing stress measurement campaign at an underground liquefied petroleum gas storage project which locates in ZhuHai, China, this paper briefly describes the various uses of stress measurement, details of hydraulic fracturing test system, test procedure adopted and the concept of hydraulic fracturing in arriving at the in-situ stresses of the rock mass.

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Predicting the azimuth of natural fractures and in-situ horizontal stress: A case study from Sichuan Basin, China

Geophysics ◽

10.1190/geo2020-0829.1 ◽

2021 ◽

pp. 1-97

Author(s):

kai lin ◽

Bo Zhang ◽

Jianjun Zhang ◽

Huijing Fang ◽

Kefeng Xi ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Seismic Data ◽

Sichuan Basin ◽

Horizontal Stress ◽

Seismic Attributes ◽

Seismic Events ◽

Natural Fractures ◽

Microseismic Data ◽

Maximum Horizontal Stress

The azimuth of fractures and in-situ horizontal stress are important factors in planning horizontal wells and hydraulic fracturing for unconventional resources plays. The azimuth of natural fractures can be directly obtained by analyzing image logs. The azimuth of the maximum horizontal stress σH can be predicted by analyzing the induced fractures on image logs. The clustering of micro-seismic events can also be used to predict the azimuth of in-situ maximum horizontal stress. However, the azimuth of natural fractures and the in-situ maximum horizontal stress obtained from both image logs and micro-seismic events are limited to the wellbore locations. Wide azimuth seismic data provides an alternative way to predict the azimuth of natural fractures and maximum in-situ horizontal stress if the seismic attributes are properly calibrated with interpretations from well logs and microseismic data. To predict the azimuth of natural fractures and in-situ maximum horizontal stress, we focus our analysis on correlating the seismic attributes computed from pre-stack and post-stack seismic data with the interpreted azimuth obtained from image logs and microseismic data. The application indicates that the strike of the most positive principal curvature k1 can be used as an indicator for the azimuth of natural fractures within our study area. The azimuthal anisotropy of the dominant frequency component if offset vector title (OVT) seismic data can be used to predict the azimuth of maximum in-situ horizontal stress within our study area that is located the southern region of the Sichuan Basin, China. The predicted azimuths provide important information for the following well planning and hydraulic fracturing.

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Predicting Hydraulic Fracturing in a Carbonate Gas Reservoir in Abu Dhabi Using 1D Mechanical Earth Model: Uncertainty and Constraints

10.2118/spe-172942-ms ◽

2015 ◽

Author(s):

Manhal Sirat ◽

Mujahed Ahmed ◽

Xing Zhang

Keyword(s):

Hydraulic Fracturing ◽

Hydraulic Fracture ◽

Natural Fracture ◽

Abu Dhabi ◽

Hydraulic Fractures ◽

Gas Reservoir ◽

In Situ Stresses ◽

Tight Carbonate ◽

Different Depths

Abstract In-situ stress state plays an important role in controlling fracture growth and containment in hydraulic fracturing managements. It is evident that the mechanical properties, existing stress regime and the natural fracture network of its reservoir rocks and the surrounding formations mainly control the geometry, size and containments of produced hydraulic fractures. Furthermore, the three principal in situ stresses' axes swap directions and magnitudes at different depths giving rise to identifying different mechanical bedrocks with corresponding stress regimes at different depths. Hence predicting the hydro-fractures can be theoretically achieved once all the above data are available. This is particularly difficult in unconventional and tight carbonate reservoirs, where heterogeneity and highly stress variation, in terms of magnitude and orientation, are expected. To optimize the field development plan (FDP) of a tight carbonate gas reservoir in Abu Dhabi, 1D Mechanical Earth Models (MEMs), involving generating the three principal in-situ stresses' profiles and mechanical property characterization with depth, have been constructed for four vertical wells. The results reveal the swap of stress magnitudes at different mechanical layers, which controls the dimension and orientation of the produced hydro-fractures. Predicted containment of the Hydro-fractures within the specific zones is likely with inevitable high uncertainty when the stress contrast between Sv, SHmax with Shmin respectively as well as Young's modulus and Poisson's Ratio variations cannot be estimated accurately. The uncertainty associated with this analysis is mainly related to the lacking of the calibration of the stress profiles of the 1D MEMs with minifrac and/or XLOT data, and both mechanical and elastic properties with rock mechanic testing results. This study investigates the uncertainty in predicting hydraulic fracture containment due to lacking such calibration, which highlights that a complete suite of data, including calibration of 1D MEMs, is crucial in hydraulic fracture treatment.

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Hydraulic Fracturing to Improve Nutrient and Oxygen Delivery for In Situ Bioreclamation

In Situ Bioreclamation ◽

10.1016/b978-0-7506-9301-1.50009-3 ◽

1991 ◽

pp. 67-82 ◽

Cited By ~ 2

Author(s):

Wendy J. Davis-Hoover ◽

Lawrence C. Murdoch ◽

Stephen J. Vesper ◽

Herbert R. Pahren ◽

Omar L. Sprocket ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Oxygen Delivery

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Fracture Initiation and Propagation in a Deep Shale Gas Reservoir Subject to an Alternating-Fluid-Injection Hydraulic-Fracturing Treatment

SPE Journal ◽

10.2118/195571-pa ◽

2019 ◽

Vol 24 (04) ◽

pp. 1839-1855 ◽

Cited By ~ 12

Author(s):

Bing Hou ◽

Zhi Chang ◽

Weineng Fu ◽

Yeerfulati Muhadasi ◽

Mian Chen

Keyword(s):

Hydraulic Fracturing ◽

Shale Gas ◽

Fracture Initiation ◽

Fluid Injection ◽

Hydraulic Fractures ◽

Stress Difference ◽

Gas Reservoirs ◽

Complex Fracture ◽

Initiation And Propagation

Summary Deep shale gas reservoirs are characterized by high in-situ stresses, a high horizontal-stress difference (12 MPa), development of bedding seams and natural fractures, and stronger plasticity than shallow shale. All of these factors hinder the extension of hydraulic fractures and the formation of complex fracture networks. Conventional hydraulic-fracturing techniques (that use a single fluid, such as guar fluid or slickwater) do not account for the initiation and propagation of primary fractures and the formation of secondary fractures induced by the primary fractures. For this reason, we proposed an alternating-fluid-injection hydraulic-fracturing treatment. True triaxial hydraulic-fracturing tests were conducted on shale outcrop specimens excavated from the Shallow Silurian Longmaxi Formation to study the initiation and propagation of hydraulic fractures while the specimens were subjected to an alternating fluid injection with guar fluid and slickwater. The initiation and propagation of fractures in the specimens were monitored using an acoustic-emission (AE) system connected to a visual display. The results revealed that the guar fluid and slickwater each played a different role in hydraulic fracturing. At a high in-situ stress difference, the guar fluid tended to open the transverse fractures, whereas the slickwater tended to activate the bedding planes as a result of the temporary blocking effect of the guar fluid. On the basis of the development of fractures around the initiation point, the initiation patterns were classified into three categories: (1) transverse-fracture initiation, (2) bedding-seam initiation, and (3) natural-fracture initiation. Each of these fracture-initiation patterns had a different propagation mode. The alternating-fluid-injection treatment exploited the advantages of the two fracturing fluids to form a large complex fracture network in deep shale gas reservoirs; therefore, we concluded that this method is an efficient way to enhance the stimulated reservoir volume compared with conventional hydraulic-fracturing technologies.

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