Over the past decade, drilling operations have faced a lot of serious drilling challenges like transit planning, structural strength, jacking operation, dynamic positioning analysis, mooring analysis and foundations failures as a result these challenges had a critical effect on people, assets or environment. Therefore, in the oil industry; specialists were deployed to assess the nature of the hydrocarbon bearing zone as well as the subsurface geology to interpret any possible risk. Specialists are also assigned other responsibilities such as well designing, right hole-path selection. Choosing the contractor, equipment, and all other systems required to complete the project safely is also a task for the specialist to complete. Furthermore, they provide the employees with health and safety information along with its effective safety training to avoid any potential risk and injuries.
Figure (1) shows how there is a decline in the drilling, production and exploration risk along with the decline of injuries over the past decade. A decline in injuries proves that the HSE (Health, Safety, and Environment) has developed in last couple of years. Figure (2) displays a rotary cycle that shows how various aspects of HSE risk management are handled. HSE policies are carefully maintained to prevent risks including harsh environment, high Pressure, high Temperature wells and availability of sour gas. Risks associated with the particular operation are adequately addressed by the rig’s HSE Management System (HSE-MS).
Mud Report
Mud plays a very important role in the process of drilling and greatly helps in the exploratory purposes. This proves the need to examine how mud and its properties affect the drilling process in order to maximize the benefits of the same. It is in this light that this reports keenly examines the relation between the use of mud in the drilling processes and the depth of holes. Researchers prove that the drilling rates that use mud in the process of drilling vary between 30 to 70 percent as compared to the drilling that is obtained by the use of water and the same conditions of drilling. The causes of reduction are such as fluid viscosity that affects the rate of drilling due to the cleaning action and lubrication properties that affects entail emulsification of drilling holes. Mud, as a component of drilling fluid greatly plays a crucial part in drilling and some of its major functions include controlling wellbore pressure, lubricating and cooling the drill bit, carrying the drill cuttings among others. In order to ensure that mud used in drilling fulfill all the tasks, there must be added selected additives to help in controlling the required properties of mud. It is in this light that a mud engineer is tasked with ensuring that any new mud produced and added to the process of drilling meets that required specifications. This requires that there is recording of mud properties, usage of product and the inventory on daily basis. In this manner, there is need to carry out mud calculations to understand on the effects of mud on the drilling processes.
Mud weight calculationsÂ
Table (1) shows the mud weights encountered during the drilling duration and the hydrostatic pressure caused by the weights. Their calculation is ultimately considered on both the depth and the mud weight. These calculations estimate the pressure at every stage of the drilling phase and illustrate the processes that are supposed to carry out. The following equations were used to get the mud weight and the hydrostatic pressure.
• Mud weight =
• Hydrostatic pressure = Pressure gradient * TVD
Table 1: Mud weight calculation
Depth (ft)
Mud Weight (ppg)
Hydrostatic pressure
4151
83
17915.72
4151
83
17915.72
4151
83
17915.72
4151
83
17915.72
4151
83
17915.72
4151
83
17915.72
2699
65
9122.62
2917
67
10162.83
3733
68
13199.89
3733
68
13199.89
3733
68
13199.89
3733
68
13199.89
4180
78
16954.08
5163
78
20941.13
5945
78
24112.92
6979
78
28306.82
7640
78
30987.84
7916
78
32107.3
7916
78
32107.3
7916
78
32107.3
7916
78
32107.3
7916
78
32107.3
7916
78
32107.3
7916
80
32930.56
7916
80
32930.56
Conclusion
 Horizontal wells are known for their high production rates and high recovery of reserves. Unlike vertical wells, the horizontal wells expose more formation to production, which causes the pressure to fall from the formation into the bore. The most common technique for drilling horizontal wells is the use of multiple wells and locate them throughout the reservoir. This approach reduces resistance
The drilling project was successful in the scheduled 25 days. The team plays utilized most of the allocated time productively, and they were able to drill a horizontal well that could achieve maximum and long-term oil productivity. Records also imply that $2,040,350 was spent on that drilling exercise. Moreover, the Inclination angle was 86 to 89 degrees for a considerable distance, which indicates that the drill is a horizontal well. The daily drilling report also suggests that much of the time was spent on drilling. I suggest a contingency cost estimation approach for this project, with the main aim of including all the unpredictable risks in the budgeting process.
References
[1] f, “Notes on horizontal well drilling and Completions”, 2016. [2] S. O. Osisanya, “Fundamentals of Drilling and Completion”, 2016. [3] G. Nygaard and G. Nævdal, “Nonlinear model predictive control scheme for stabilizing annulus pressure during oil well drilling”, Journal of Process Control, vol. 16, no. 7, pp. 719-732, 2006. [4] J. Zhou and M. Krstic, “Adaptive predictor control for stabilizing pressure in a managed pressure drilling system under time-delay”, Journal of Process Control, vol. 40, pp. 106-118, 2016. [5] D. Smith and R. Kennedy, “Drilling towards HSE excellence”, SPE European Health, Safety and Environmental Conference in Oil and Gas Exploration and Production, 2011. [6]C. Dawson and H. Verkuil, “From a Daily Drilling Report to a Data and Performance Management Tool”, SPE Intelligent Energy Conference & Exhibition, 2014.
