English to French Tech/Engineering Petroleum Eng/Sci gas well monitoring

The fracture gradient is calculated from offset well leak off data and observed instances of lost circulation. Generally, although mud losses while drilling are often observed, they are not predictable and the wellbore instability observed in many wells while drilling is interpreted as having origins in local and regional geomechanical stresses, reactions between the drilling fluid and formation chemistry, and drilling practice such as hole cleaning, mud weight selection and tripping regime or, a combination of these factors