Drilling operations are faced with conditions of subsurface uncertainty with unexpected drilling hazard potential. Operation is done in 24 hours a day continuously, until drilling is declared complete. The consequence of this work environment is the potential for high work accident, one of which is caused by situational conditions in the field that allow the communication limitations in clear and detailed.
Such conditions may include high-noise working conditions, limited visibility due to weather hazards (rain, fog, dark / night), and sour gas exposure. In this condition, often verbal communication is followed by non verbal communication, either in the form of the use of horns (morse), flag raising (semaphore) and limb movements. Non-verbal communication will be more urgent if the drilling operation conditions in emergency conditions, such as the occurrence of kick, blowout and exposure to sour gases. Non-verbal communication occasionally used in any drilling site does not have standardization, thus increasing the potential for communication errors.
Methods Non-verbal instructions intended in this paper is a sign language that serves as a medium for delivering work orders (instructions). This non verbal instruction uses one limb, represented by at least 2 limb movements in at least 2 stages of movement, to interpret a command or work instruction. If less than 2 movements or less than 1 stage of movement, then the movement of the body may have meaning, but can not be implemented because the instructions are not complete
With the invention, paper and efforts of this standardization, the communication process and the delivery of orders in both normal and emergency conditions at the drilling sites can be carried out in a structured, standardized, clear, detailed and widely applicable manner. The instruction method in the form of non-verbal codes is named: NS Blind Code Drilling, which has been registered since December 2014 to the Directorate General of Intellectual Property Rights and is in process related to the patent application.
Due to its capacity and stability in extreme subsurface conditions, such as in HTHP and high concentration of sour gas and because of its non corrosive, re-useable, low cost and environmentally friendly, high-density Phosphate based Completion Fluid (CF) has been used in several exploration wells in Indonesia.
The main challenges during testing in exploration wells with extreme subsurface condition and high concentration of sour gas was how to maintenance and keep CF stability properties to support operating testing devices.
In exploration well KRE-1 in West Java Field, in a fracture Metasediment and Conglomerate lithology, subsurface conditions of HTHP, H2S 21 ppm, and CO2 25%, the Non Productive Time (NPT) that related with testing was 202.5 hours due to the constraints in the testing device, both the string configuration and the rubber component, it were caused by unfamiliarity in handling this brine.
After the evaluation, we changed the CF field handling and changed a configuration and specification of testing device. The result showed that the CF properties became stable and the operational testing worked well.
The same procedures were applied in three exploration wells from different fields with several characteristics lithology and subsurface. First well BOP-1 in Bunyu island Field, in Sand-Shale-Silt-Coal lithology with subsurface condition of swelling shale with loose sand. Second well TBR-1 in East Java Field, Limestone lithology with subsurface condition of high concentration H2S up to 20.000 ppm and CO2 35%. Last well, KRT-1 in fracture Metasediment, Conglomerate, Sandstone and Limestone lithology and subsurface condition of HTHP, H2S 13 ppm, and CO2 6%. The related NPT with testing gradually dropped to 119.5 hours and then 78 hours and finally only 2 hours.
This paper describes the field experiences of handling Phosphates based CF during testing with lessons learned for operational testing devices from testing companies.