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Well cementing is the process of introducing cement to the annular space between the well-bore and casing or to the annular space between two successive casing strings.〔Economides, M. (1990). ''Well Cementing''. (E. B. Nelson, Ed.) Sugar Land, Texas: Schlumberger Educational Services.〕 ==Cementing Principle== # To support the vertical and radial loads applied to the casing # Isolate porous formations from the producing zone formations # Exclude unwanted sub-surface fluids from the producing interval # Protect casing from corrosion # Resist chemical deterioration of cement # Confine abnormal pore pressure # To increase the possibility to hit the target Cement is introduced into the well by means of a cementing head. It helps in pumping cement between the running of the top and bottom plugs. The most important function of cementing is to achieve zonal isolation. Another purpose of cementing is to achieve a good cement-to-pipe bond. Too low an effective confining pressure may cause the cement to become ductile. For cement, one thing to note is that there is no correlation between the shear and compressive strength. Another fact to note is that cement strength ranges between 1000 and 1800 psi, and for reservoir pressures > 1000 psi; this means that the pipe cement bond will fail first. This would lead to the development of micro-annuli along the pipe.〔Lyons, W. C. (Ed.). (1993). ''Handbook for Petroleum and Natural Gas Engineers'' (Vol. 1). Houston: Gulf Publishing Company.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Well cementing」の詳細全文を読む スポンサード リンク
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