... wells were analyzed. Furthermore, the influence of drilling azimuth, in-situ stress value and formation strength on the fracture modes of horizontal wells was analyzed. The results show that: the possibility of tensile fracture is greater when drilling horizontal wells near the maximum horizontal stress...

... different measurement spots; therefore, the Shoerey s Model is taken to process all the measurements, and then the magnitude of stresses at the cavern section is determined accurately; the maximum horizontal stress is 11.02±1.0MPa, and minimum horizontal stress is 6.82±1.0MPa; the orientation of maximum...

... are dominated by horizontal stresses, the tectonic stresses take absolute predominance, with the maximum horizontal principal stress up to 42.19 MPa, and the minimum horizontal principal stress up to 22.8 MPa. However, the in-situ stress fields are dominated by gravity stresses in Huainan and Pingdingshan coal...

... to consider in the design of the powerhouse cavern. Owing to the scarce information obtained at the design stage and to the high values of the calculated horizontal stresses, it was decided to perform additional stress measurement tests, using small flat jacks, once construction started and excavation...