During drilling, abrupt or unexpected changes in pore pressure and wellbore stability can cause substantial problems leading to costly drilling delays, unsafe incidents and potential loss of data or the well. Monitoring the state of a well in real time during drilling is critical for both mitigation of inherently uncertain predrill prognoses and proactive planning ahead of bit. Many offset wells used at the planning stage often have poor, or missing, data and may not even be representative of the conditions experienced in the wellbore being drilled. Additionally, the more complex the geological environments are, the more uncertain the pore pressure and fracture pressure predictions can be.
To help reduce these uncertainties, real time estimates based on both depth- and time-based drilling data can supply key information. Lots of data is generated during the drilling process that must be used to make quick operational focused decisions without costly delays. Data includes drilling parameters, gas and gas peak data, mud logs, logging while drilling (LWD) and wireline data such as gamma ray, resistivity and sonic, and information about the well condition and how it changes during drilling. It is very important that the monitoring process uses high-frequency (e.g. every 5-10 seconds) time-based data as well as the more standardly used low-frequency (e.g. every 0.5m) depth-based data, and in this paper we present a real time workflow which does exactly that. The results are increased use of all relevant data while drilling and a more complete database for post-well analysis.