Development of Data Base System for Lost Circulation and Analysis of the Data

Abstract

It is very important to reduce drilling costs because the cost of drilling the wells is approximately 50% in geothermal energy development for electric power generation. Lost Circulation (LC) is serious problem that contributes greatly to the cost of drilling and completion of the geothermal wells. LC also can be the cause of formation collapse and/or stuck drill strings as well as failure in casing cementing. We are developing the data base system to perform data analysis system and optimum treatment of Lost Circulation. The objective of this system is to record the LC treatment procedure and result, and to analyze the data and recommend which treatment will be best for future LC occurrences. The system is developed on PC, and it has following functions. 1) Data Input(175 items) 2) Data Base(more than 4,500 LC data are recorded) 3) Data View(List, Well diagram, Well trajectory) 4) Data Search 5) Off-line Network 6) Data Analysis 7) Temperature Data 8) LC Treatment support (Expert System) From the data analysis, 65% of LC is total loss (no circulating mud returned to the surface, however, loss severity depends on the pumped rate) in geothermal wells. Cement is used in 65% as a treatment material for total loss, and LCM is used in 30%. However, the proportion of success is about 15% with cement and about 10% with LCM.