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.
Bachtiar, A. W. (PT. Pertamina EP) | Purba, F. I. (PT. Pertamina EP) | Dusyanto, E. D. (PT. Pertamina EP) | Mucharam, L. (Institut Teknologi Bandung) | Swadesi, B. (Institut Teknologi Bandung) | Santoso, R. K. (Institut Teknologi Bandung) | Fauzi, I. (Institut Teknologi Bandung) | Hidayat, M. (Institut Teknologi Bandung) | Aslam, B. M. (Institut Teknologi Bandung) | Dzulkhairi, H. (Institut Teknologi Bandung) | Surya, A. (Institut Teknologi Bandung) | Marhaendrajana, T. (Institut Teknologi Bandung)
Injectivity is a critical issue in polymer injection since it determines the success of polymer to displace and sweep oil in the reservoir. Polymer has shear rate and temperature-dependence viscosity which is substantially different behaviorfrom water. Any calculation related to injection performance should consider this behavior. Injector should be organized to achieve the desired injection rate without any issue. The easiest approach to design the optimum injector is using IPR-TPR method. Therefore, in this paper, we develop Non-Newtonian IPR-TPR method to achieve optimum completion design of injector. The IPR equation is built using modified Darcy equation for Non-Newtonian fluid. The TPR equation is developed using
We used case study of T-048 – T-012 injector-producer in Tanjung Field Zone-C, Indonesia with 500 and 2,000 ppm HPAM polymer. Simulation results show that there exists changing process from shear thinning to Newtonian along the tubing because of temperature and injection velocity while only Newtonian behavior occurs in near wellbore for 500 ppm injection case. Smaller tubing OD produces higher effective injection rate than the bigger one. The 2,000 ppm polymer cannot enter the reservoir due to bottomhole pressure reaches the fracture presure.Finally, smaller tubing OD (below 2.875 in) is suitable in Tanjung Field Zone-C for 500 ppm polymer injection. 2,000 ppm polymer cannot be deployed and needed further evaluation.
This paper is expected to be a lesson Learns of using nitrate-based fluid as an alternative solution to improve drilling performance and production optimization old wells.
This Lesson Learns begins from literature studied, laboratory test, field trials and continuous improvements.
Nitrate Completion Fluids have good solubility for wide range of contaminants. Furthermore, it may have some well stimulation effects. Return permeability testing of sandstone coring samples after immersion fluid completion Nitrate, in some conditions, showed some increase in the value of return oil permeability (Ko) from 25.55 to 36.25 mD.
In the field of applications, it has been tested as an additive and drilling mud on one of the deepest wells in Indonesia (5850 m) in Seram. As the additive, used in NaCl polymer mud system in order to reduce levels of solids and chloride, without changing the other mud properties significantly. With decreased levels of chloride, the corrosion rates of drilling and production equipments are also decreased. As a completion fluid, Nitrate CF have been used in the workover wells in South Sumatra and Riau. As a washer on perforation wash job, it is capable of delivering up to 20x increase in oil production and gas production compared to the previous 3x. Operationally, it has not been recorded for any Non Productive Time related this fluid.
Nitrate based fluid is an alternative completion fluid products that have been developed as an additive, mud drilling and stimulation fluids. Nitrate based fluid is sold in powder or liquid forms. Nitrates are also the basic ingredient of fertilizer. Nitrate Completion fluids have a density specification up to 1.75, the corrosion rate is lower than 10 MPY @350 deg F with standard carbon steel corrosion coupon, 5 NTU turbidity and pH 6-9, with pH buffering capacity, so it has a resistance to contamination of sour gas, having properties endotermic and environmentally friendly reaction.
This paper is a case study of field data, assessing the impact of a well integrity survey on an ongoing development drilling programme, enabling critical management of an unexpected shallow gas risk. The results and conclusions presented are applicable to the diagnosis and risk management of shallow gas zones and their impact on well construction, design and integrity. The well Operator experienced a severe loss of well control during drilling operations in the Western Block of Talang Jimar field in Sumatra. The field is mature and the well was considered routine in a series of more than 200 drilled over the past 50 years. A kick occurring at a relatively shallow depth around 300m was completely unanticipated. It was judged critical to further drilling to investigate the location and extent of the charged interval. This would identify HS&E and operational risks to be mitigated by modification of both the ongoing drilling plan and the well design. The clearest and most precise information was required. When active surface gas venting was discovered at an adjacent well, an ultrasonic annular integrity survey was commissioned to determine the subsurface source of the gas.
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.
This paper presents an integrated and simplified method with some field cases that can be applied to delay rapid production depletion and it focuses on the occurrences of the potential bypassed oil zone. The method that we used in here is by combining geological approach,with reservoir production history map as a result of data obtained during infill drilling and subsequent well work activities in the wells in the aim to get the remaining potential of reservoir. The primary benefit is to extent the field life as long as possible before it become a Marginal Field.
Well services are the common ways in maintaining production in every field, in this case Sengata Field. This aging onshore field has been developed by PT PERTAMINA EP since 1973 and the production reached its peak of 6000 BOPD in 1979 and with average decline rate of 60%, the field is on a fast declining trend. Like many other deltaic environment reservoirs in the world, the structures of this field is extremely sophisticated and consist of large number of reservoirs and most of them are thin bed reservoir and multiple stacked channels that contain oil, gas and formation water. The observed drive mechanisms consists of a combination of Solution Gas Drive and Water Drive The complicated geometry is a serious challenge for engineers who are responsible for determining lateral and vertical communication between the individual sand units.
Recent analytical method has been proven very successful in sustaining and revitalizing production shown by the oil increment up to 110% for it's target and allows PERTAMINA EP to optimize and prolong the field life.