In the process of drilling, drilling fluid will invade into bedding plane shale under action pressure difference that cause hydration collapse and wellbore instability. order to ensure stability during oil gas it is necessary clarify invasion law along fractures process. The immersion experiment method often used study fluid, which quite different from actual underground. this paper, depth conf...

PURPOSE This study investigated the effects of multiple drilling on the immature capital femoral epiphysis following ischemic injury in a piglet model. MATERIALS AND METHODS Ischemic necrosis of capital femoral epiphysis was induced bilaterally in 12 piglets using a cervical ligation method. Three weeks later, medial, central, and lateral 3 drill holes were made on the left femoral head using...

Two deep geothermal wells, one of which is the deepest onshore UK well, have been successfully drilled to intersect Porthtowan Fault zone in early Permian high heat flow Carnmenellis Granite, part major post-Variscan Cornubian batholith underlies SW England. The drilling target was prognosed at 4 5 km depth from existing surface data and limited geophysics. It a late Variscan complex strike-sli...

Loss of circulation while drilling is a challenging problem that may interrupt operations, reduce efficiency, and contaminate the subsurface. When drilled borehole intercepts conductive faults or fractures, lost manifests as partial total escape drilling, workover, cementing fluids, into surrounding rock formations. control materials (LCM) are often used in mitigation process. Understanding fra...

Fractures are crucial as main natural gas transport channels in tight sandstone reservoirs. In order to reveal the correlation between combination of fractures Block Keshen 2 and sandstone, we have collected drilling core data, logging curve imaging rock thin-section data from Bashjiqike Formation area, by classifying statistically analyzing different influencing factors fractures, established ...

increasing the thermal stability and resistance to bacterial attack (bioresistance) of the potato starch used in the water-based drilling fluid is the aim of this work. four types of potato starch grafted with acrylamide and a mixture of each one with acrylic acid, 2-acrylamido-2-methyl-1-propane sulfuric acid and itaconic acid were synthesized by manganese (iv)-induced redox system at the suit...

With the development of shale gas exploration in China, use conventional logging tools has been introduced, and cross multipole array acoustic have gradually used to determine stress orientation shale. The direction fast shear waves (FSWs) is generally parallel horizontal maximum principal compression (SHmax). However, azimuth FSWs found be main strike (but not SHmax) structural fractures reser...

SUMMARY The orientation of SHmax is commonly estimated from in situ borehole breakouts and earthquake focal mechanisms. Borehole measurements are expensive, therefore sparse, can only be made regions with many well-characterized earthquakes. Here, we derive the stress-field using stress-induced anisotropy nonlinear elasticity. In this method, measure strain derivative velocity as a function azi...

K e y w o r d s F o u r t h g r a d e fluid, Unsteady flow, Lie symmetries. 1. I N T R O D U C T I O N In recent years, considerable efforts have been usefully devoted to the s tudy of flow of nonNewton ian fluids. This is ma in ly due to their m a n y appl icat ions in pe t ro leum drilling, manufactu r ing of food and paper, and other similar activities. A vast a m o u n t of l i te ra ture i...

This paper examines the diverse nature of user reactions to information technology (IT) within the social-historical context of its organizational use. Employing activity theory as a conceptual framework, we conduct an interpretive analysis of physicians work, perceptions, and IT usage experience at a large community hospital to understand why some of these physicians were favorably disposed to...