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Accident rates in academic laboratories are increasing rapidly day to day. The incorporation of complex activities with the inclusion of modern technologies and human behavior during experiments often makes it difficult to manage health and safety risks. Failure modes and effect analysis (FMEA) is widely used risk assessment technique that consider (03) risk parameters which include severity (S), occurrence (O), and detection (D), and calculate a risk priority number (R.P.N), which facilitates in failure modes ranking. However, there are some shortcomings associated with this method. This study aims to propose a framework for prioritizing the health and safety risks (failure modes) in an experiment using a widely used Multi-criteria decision-making method, i.e., Fuzzy VIKOR supported by criteria objective weights determined using the Shannon entropy concept. The fuzzy VIKOR method is employed to rank the failure modes based on the maxi group utility and the minimum individual regret. In this study, an experiment related to preparing rock core samples is taken as an example for implementing the proposed technique. Core sample preparation is one of the most common and dangerous experiments in the petroleum industry. The performance of the experiment allows rock sample preparation of desired shape and size to be tested for its hydrocarbon producing potential. The final results indicate that applying the proposed method in a fuzzy environment can efficiently prioritize the experiment’s health and safety risks, which is further considered for the implementation of control measure prioritization. The proposed approach can be applied to other experiments with the same or different domains.

Asphaltene precipitation and its subsequent deposition always remain a major concern for Oil industry. Formulation of a comprehensive and reliable risk management system for asphaltene prone wells and fields is a challenging task because of the influence of diverse factors. In this study, a decision support system is developed for the asphaltene risk assessment in wells and fields. Since, the data present in the literature is scarce and not consistent, therefore, a hypothetical data of fields and their wells was considered to conduct the study comprehensively. Three hypothetical fields namely; Field A, Field B and Field C were assumed and in each field ten wells were taken into consideration. A decision support system for assessing the risk of asphaltene prone wells was developed using one of the popular and powerful multi-criteria decision making technique i.e. Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (Fuzzy TOPSIS) coupled with Analytic Hierarchy process (AHP). The risk of wells was evaluated using three criteria namely; Detection, Severity and Controls. These criteria were further sub-divided into sub-criteria and their data was assumed. The assumed data was transformed into Triangular fuzzy numbers for calculations. According to the final outcomes, Field A was proved be the most risky field followed by Field B and in the last comes Field C. The outcomes were further validated by other method namely; Fuzzy Complex Proportional Assessment (COPRAS) and all TOPSIS outcomes were found in good relationship with Fuzzy COPRAS. The proposed methodology proposed in this study will be landmark in risk ranking of asphaltene prone wells and fields.

Abstract Wellbore instability is one of the major problems that arise in drilling shale formations. Drilling in these formations may lead to breakouts and induce fractures. In Pakistan, drilling companies face quiet a number of formations that are shaly in nature and are candidates for wellbore instability issues. To counter these issues, it is required to have good understanding about the composition of the shale and its chemical reactivity with drilling fluids. Shale samples of three different formations have been obtained. These samples belong to two different regions of Indus Basin of Pakistan and were subjected to cation exchange capacity test and X-rays diffraction analysis to determine the reactivity and mineralogy, respectively. The samples were then tested for swelling properties using linear dynamic swell meter. The testing was done in two different water-based drilling fluids. The increase in height and swelling percentage for each sample was then recorded against each type of drilling fluid. A comparative analysis was done as to what type of drilling fluid systems out of the two used in the swelling test would best inhibit the swelling nature of shale for each formation in these regions of Pakistan. Finally, analytical and numerical modeling was performed on each shale sample. It was observed that the swelling parameter A (total swelling) increases significantly for Middle Indus Basin Shale Formation, and on the contrary, the filtration term (C) becomes independent of time after certain period of testing.

Abstract Drilling in Barents Sea proves to be a challenging task, as this region is situated in auroral zones having high geomagnetic latitude, where magnetic interferences develop from magnetic field and magnetic materials inside subsurface are quite common. For this region, monitoring of magnetic field is utterly significant as any fluctuations can distort the tool sensor performance with ultimately enlarging the uncertainty in azimuth. To guide a well to its desire location, measurement while drilling (MWD) tool needs to be operated with utmost precision; however, its accuracy compromises as a result of magnetic interferences from drill string and nearby magnetic material. The performance of this tool depends upon its sensors. Any distortion in sensor performance can lead to problems such as multiple sidetracking and increase in overall project cost. Furthermore, the same BHA was also placed in a region of Pakistan and the impact drill string interference was observed. It was discovered that the interferences that had tremendous impact on magnetometer Z-component in Barents Sea had a drastic reduction in the region of Pakistan as it is situated in low latitude, where uncertainty in azimuth is low. In this work, an exemplary bottom-hole assembly (BHA) was analyzed and the impact of individual drill string components interferences was observed on the MWD sensors. It was perceived that the bit was responsible for creating the major distortion in MWD sensor. Apart from that, it was also investigated that the location of the well also plays a vital role in this distortion. This intervention in the sensors is created by a vast difference between the used actual length and the recommended length of nonmagnetic drill collar in the BHA. Numerically, it was investigated that if the physical distance between the sensors and bit is increased, then this interference is reduced. It was also apparent that the Z-component of the magnetometer was utterly distorted because of this interference, while the X- and Y-components were proved to be independent of these interferences. It was further examined that the effects of latitude and longitude play a significant role in the course of changing the impact of these errors on magnetization.