Is really a conductor hole (vertical well) with horizontal nicely. The target
Is often a conductor hole (vertical properly) with horizontal well. The target formation will be the shale gas reservoir within the decrease element of Upper Ordovician Wufeng Formation and lower Liuzhou Longmaxi formation. Right after inspection, the cementing high-quality of each casing and nicely section is certified From 25 November 2015 to 19 December 2015, a total of 27 sections in the shale gas well have been fractured. The initial section for the 27th section has an inclination angle of about 15 and the depth variety is 3533530 m. In accordance with the relevant geological information, the remaining parameters (see Table 4 under) are obtained for the calculation. The formation temperature gradient is three C/100 m, plus the rock mechanical parameters of cement and their variation pattern with temperature are obtained primarily based around the present formula technique. Except for the 8th, 9th and 11th fracturing sections, the maximum average operating stress of every section is within their respective theoretical load range. The calculated security loads from the 8th, 9th and 11th fracturing sections are 96.6, 95.85, and 91.55 MPa, plus the actual operating pressures are 108.1, 106.3, and 97.23 MPa, which are respectively 10.21 , 10.09 , and six.15 greater than the theoretical values. Therefore, within the 8th, 9th and 11th fracturing section, it can be probably that soon after various fracturing, the 3-Chloro-5-hydroxybenzoic acid site pressure state of cement will exceed the yield state, that will lead to large plastic deformation and cementing failure.Table four. Connected calculation parameters. Casing Parameters E1 = 210 GPa = 0.2 Environmental Parameters Depth; 3533530 m P0 = 7416 MPa Structure Parameters ai = 127.36 mm bi = 139.7 mm a = 139.7 mm b = 233.45 mmAccording to field observation, after a series of fracturing operations, the J effectively annulus sealing problems came out. As a result, to a particular extent, it may be verified that the evaluation system has a particular reference worth. eight. Conclusions As outlined by the actual engineering challenges, this paper establishes a mechanical model in the cement sheath primarily based on the properties of cement as well as the actual engineering practice. Moreover, shakedown theory is carried out on the sheath, combining the compression experiments under various conditions. Thus, the influence of temperature on the sheath has been clarified. Based around the present cement formula system and geological atmosphere, we are able to conclude: 1. When only the temperature inside the sheath varies cyclically, the array of cyclical changes in temperature brought about by the operation PF-06454589 Biological Activity procedure has a negligible effect around the sheath. When the fracturing stress and temperature act collectively on the sheath, the effect of temperature on it is reflected in two elements. The temperature stress due to the existence in the distinction between the internal and external surface causes the maximum cyclic load declining; nevertheless, the change in temperature causes the material parameters with the cement to alter. The impact of temperature pressure on sheath is proportional to the T. The bigger the temperature difference is, the higher the is. When the T ranges from 70 to 110 C, the negative impact of temperature stress on the total stress accounts for about six . The influence of temperature on the material properties of cement is as follows: together with the rising of temperature, the cohesion of cement declines, along with the internal friction angle increases. The plastic traits on the cement is often enhanced. With the modify of T, the adverse impact with the Pmax ascends slowly. Com.
