Integrating risk management concepts into the drilling non-productive time

Introducing the non-productive time (NPT) concepts in the 1960s was a necessity dictated by the ever-increasing cost and complexity of the oil and gas well drilling. The NPT definition stayed unsettled until two decades later, the definition converged toward its accepted current definition of “the time when planned or out-of-plans drilling-related activities do not add value to the operation objectives.” NPT as it is defined in drilling nowadays is a form of time waste or loss which adversely impacts the overall efficiency of the drilling operation. Since the 1980s, risk management (RM) has become a sound technique to evaluate operational losses or wastes of many resources, including time. This paper presents an attempt to couple RM techniques with NPT philosophy together with other concepts such as Systems Thinking, Synergy, Continuous Improvement, and Total Quality. These concepts and derived techniques suit well controlling the intolerable waste that shows up in the form of delay in operations and materializes into most of the undesirable costs of drilling. These concepts, adopted herein, were applied on data from 60 rigs which were used to drill 250 wells for a period of 1 year of operation. In all 19 types of NPT were considered. A Java software model was developed and used to express NPT as an undesired event with probability of happening, in order to follow with RM terminology. The probability levels (related to the NPT values) for each rig were then defined and further classified into the four familiar ranks and their colors as used in RM: Acceptable (green), Tolerable (yellow), Inadmissible (orange), and Unacceptable (red). A matrix was established for all NPT categories and for the 60 rigs and was then named Rig-NPT Risk Matrix. A maximum probability ceiling was established as a reference for unacceptable risks of all NPT categories and for all the 60 rigs. Finally, sets of risk control recommendations were proposed to minimize the NPT in order to improve rigs performance. The concept of NPT and the science of RM when integrated gave a new approach to minimize the drilling losses. Using NPT analysis coupled with risk management was used to indicate where to optimize exerted efforts in order to synergize improvement of overall drilling performance.

KEAUSAN CRANK PIN JOURNAL CRANKSHAFT PADA DIESEL ENGINE GENERATOR DI. MV. KARTINI BARUNA

Crankshaft merupakan komponen mesin yang bekerja mengubah gerak lurus bolakbalikpiston dengan perantara batang piston menjadi gerak putar. Untuk mengubahnya,dengan proses sebuah crankshaft membutuhkan pena engkol (crank pin, sebuah bearingtambahan yang diletakkan di bagian ujung batang penggerak pada tiap silinder. Mengingat pentingnya fungsi crankshaft maka keberadaan komponen mesin tersebutharus dirawat dengan baik. Dalam penelitian ini penulis menggunakan metode fault treeanalysis, yaitu metode analisa yang digunakan apabila terdapat suatu kejadian yang tidakdiinginkan atau undesired event terjadi pada suatu sistem. Sistem tersebut kemudiandianalisa dengan kondisi lingkungan dan operasional yang ada. Dengan melaksanakan prosedur tersebut diharapkan sistem operasional dieselgenerator dapat berfungsi secara normal dan maksimal, sehingga kegiatan pelayaran danperusahaan tidak mengalami kerugian yang disebabkan terganggunya operasional kapal.Pada akhir bagian penelitian. Penulis menyajikan kesimpulan dan saran.

Development and Execution of Consequence Assessment for Liquid Pipeline Facilities

Risk assessment is an effective and commonly practiced process in industry, including oil and gas sector, as a basis for designing new pipeline terminals and stations and managing integrity of existing facilities. A holistic risk assessment method, which could be qualitative or quantitative, includes both the likelihood and consequence assessments of an undesired event. Prior to 2015, Enbridge Pipelines employed a qualitative risk assessment algorithm to assess the likelihood and consequence of a failure of liquids pipeline facilities. Over the past decade Enbridge has identified a number of shortcomings with the qualitative approach, necessitating the development and use of Quantitative Risk Assessment (QRA) to support consistency and defensibility in risk-informed decision making. A QRA requires rigorous quantitative algorithms to measure public and environmental safety, and potential business consequences of an undesired event at a facility. While significant literature has been produced, and considerable effort has been expended to quantify the potential impacts of a flammable product release on public safety, very limited work has been done on the quantitative measurement of environment related impacts. In particular, limited research has been successful in aggregating environmental consequences, public safety and business consequences to estimate the total consequence of a liquid hydrocarbon release within a pipeline facility. The consequence assessment of an unwanted event conducted through QRA can be combined with the associated likelihood to provide a quantitative measure of risk. This risk level may be used to support organizations in making risk informed decisions and in analyzing and treating facility risks, specifically in the: • Identification of top risk facilities and high consequence functional areas; • Identification of assets posing the most risk and worst case consequences; • Understanding of system reliability risk and opportunities to optimize facility operation; • Prioritization of facility maintenance projects in the capital and operating budget processes; • Supporting regulatory requirements and expectations; • Presentation of risk down to the equipment or component level; and • Understanding of residual risk and achieved risk reduction. This paper describes the development of a consequence model that monetizes the quantitative measure of public and environment safety, and potential business losses for a liquid product release at pipeline facilities. The proposed model characterizes the severity of impact of released product, expressed in dollars per event, as a function of system volume, proximity and category of receptors, asset location, and available controls.

PENERAPAN METODE FAULT TREE ANALYSIS UNTUK MENGANALISA KURANGNYA SUPPLY AIR TAWAR KE AKOMODASI KARENA KETIDAKNORMALAN KERJA HYDROPHORE TANK

Untuk menjaga kualitas dan kuantitas air tawar di atas kapal, salah satunya dapat menggunakan sistem suplai air tawar untuk kebutuhan air tawar di atas kapal, dengan menggunakan hydrophore tank suplai air tawar di atas kapal bisa terpenuhi sampai ke akomodasi dengan baik, mensuplai air tawar dari kamar mesin ke akomodasi yang tetap berkualitas meskipun dalam penampungan dalam tangki air tawar yang lama dan air tawar itu tidak banyak yang menurun kualitasnya. Apabila kebutuhan akan air tawar itu tidak terpenuhi pada saat kita akan berlayar, maka perlu dilakukan bunker air tawar agar kebutuhan air tawar di atas kapal dapat tercukupi. Metode yang digunakan dari penelitian ini adalah fault tree analysis yang mengahasilkan faktor-faktor yang dapat mempengaruhi ketidaknormalan kerja hydrophore. Fault Tree Analysis adalah metode analisa, dimana terdapat suatu kejadian yang tidak diinginkan disebut undesired event terjadi pada sistem, dan sistem tersebut kemudian dianalisa dengan kondisi lingkungan dan operasional yang ada unik menemukan semua cara yang mungkin terjadi yang mengarah pada terjadinya undesired event tersebut. Metode ini dilakukan dengan pendekatan yang bersifat top down, yang diawali dengan asumsi kegagalan atau kerugian dari kejadian puncak (Top Event) kemudian merinci sebab-sebab suatu Top Event sampai pada suatu kegagalan dasar (Root Cause). Tujuan dari penelitian ini adalah untuk dapat mengetahui apa saja yang mempengaruhi ketidaknormalan kerja hydrophore tank terhadap suplai air tawar ke akomodasi di MT. Sambu dengan menggunakan metode fault tree analysis yang menghasilkan faktor-faktor yang dapat mempengaruhi ketidaknormalan kerja hydrophore tank ketika beroperasi dan berhenti terlalu sering, masalah suplai air tawar, masalah pada feed water pump dan relief valve bermasalah. Hasil penelitian ketidaknormalan kerja hydrophore tank terhadap supply air tawar ke akomodasi, penyusun dapat menyimpulkan faktor-faktor yang tidak dapat lagi diselidiki dari setiap penyebab top event yaitu feed water pump tidak bekerja dengan baik, mengalami masalah pada suplai air tawar, dan mengalami masalah pada relief valve.

Study on the Analysis of Near-Miss Ship Collisions Using Logistic Regression

Generally, risk assessment for a ship collision can be performed by analyzing the trajectories of two ships as they get close to each other. A near-miss collision between ships is an undesired event that did not result in collision, but had a high risk of doing so. Due to the high frequency of these occurrences, many actual accident data samples can be obtained. In this paper, we extract various variables related to near-miss collisions from this data, such as Distance to Closest Point of Approach (DCPA), Time to Closest Point of Approach (TCPA) and Collision Avoidance Variance (CAV). To assess near-miss collision risk, logistic regression analysis is performed by categorizing encounter types based on ship trajectories collected over 4 months in coastal water areas.

Risk assessment in transportation systems

The paper presents problems of hazard identification in transportation systems, where not only field of action is large but also cause-consequences relations between failure causes and losses are distant in time and space. It is observed in transportation systems of goods and passengers, systems of water, gas, oil distribution and electro-energetic nets. Proposed systemic approach based on system elements classification on active (casual) and passive ones (affected). There are described concepts of vulnerability (damageability), resilience (ability of recovering and risk controlling by introducing safety measures to undesired event chain.

Reduction of the effect of actuator saturation with periodic servo-constraints

Saturation is an undesired event in trajectory tracking control of mechanical systems. When the actuators of a robotic device saturate, the solution of the inverse dynamics problem cannot fully be realized, which results in deviations from the desired trajectory and loss of performance. It is generally hard to consider the limited actuator torques and the corresponding nonlinear effects in the control design. The most common way to handle the problem is recalculating the control forces and trying to adjust the desired trajectory such that saturation will not happen. In contrast we propose a switched control approach, where, upon saturation, different sets of inputs are varied periodically to keep the reference point of the robot on the desired trajectory. For this, the desired motion is formulated by means of servo-constraints, and the periodic switching of these constraints is adjusted according to the variation of a new, manipulability type performance measure. It is demonstrated that the proposed controller can effectively reduce the trajectory following error due to actuator saturation. A typical robotic benchmark example is provided to show the application of the method, and to compare it with other approaches taken from the literature.

SCENARIO OF AN ACCIDENT OF SOIL DAMS IN CASE OF WATER SPILL OVER A DAM CREST BY USING FAULT TREE ANALYSIS

The scenario of a hydrodynamic accident of water flow over a crest of a soil dam is considered by the method of fault tree analysis, for which the basic reasons and controlled diagnostic indicators of an accident have been defined. Logical operators “AND”/”OR” were used for creation of a sequence of logically connected events, leading to an undesired event in the scenario of accident. The scenario of the accident was plotted in case of three basic reasons - an excessive settling of a dam crest, an excess flood, an inoperable spillway, taking into account the sequence of the events’ development and with observance of the necessary conditions leading to an accident. “Technical” reasons were observed in the present scenario, force majeure events were not considered. The provided scenario of the accident consists of two branches of events’ development: the left one that depends on an upstream level, and the right one that depends on settling of a dam crest. In each of the considered events an accident “the water spill over a crest of a soil dam” is possible only in case of execution of two different conditions at the same time, i.e. in case of an appropriate upstream level and the appropriate mark of a crest of a soil dam. The conditions of the accident are defined by diagnostic indices - the upstream level and settling of a dam crest, which at the same time are safety criteria of the hydraulic structure for soil dams. They allow defining the technical condition of the construction. Four possible technical conditions are suggested for the definition of technical statuses - normative, operable, limited operable, abnormal. Criteria of safety are the boundaries of the state: for loading and impact - it is the upstream level, for geometrical compliance of the construction - it is a dam crest mark.