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The potential field data like Gravity data, Magnetic data, Self-potential data, and other natural source data are accessible but hard to interpret and model. Numerous research presents ideas for modeling the potential data; however, they are mostly based on inverse or forward modeling needing a priori constraints and information. In complicated geology and tectonic setting, we do not have convenient access to a priori information to define the constraints. So, we must develop a pure geophysical interpretation method without geological constraints and minimum complexity. In this research, the Normalized Full Gradient's ability to find the gravity anomaly model was studied. The Normalized Full Gradient method is an effective method for determining anomalous bodies, such as the distribution of oil and gas fields or structural boundaries. The Normalized Full Gradient method depends on the downward analytical continuation of normalized full gradient values of gravity data. Analytical continuation discriminates certain structural anomalies which cannot be distinguished in the observed gravity field. The Normalized Full Gradient of the gravity anomaly is often used rather than the gravity anomaly itself for detecting underground spaces because it is stable and indicates the locations of source bodies. The weakness of the Normalized Full Gradient is the 3D modeling limitation, as we can only calculate the 2D response in practice. On the other hand, the responses can not describe the negative and positive parts of the anomaly. But a unique advantage of the Normalized Full Gradient is, that it does not need the primary information for gravity data modeling. In this research, we used the Normalized Full Gradient for the large-scale Bouguer gravity anomaly interpretation. Bouguer gravity anomaly wavelengths contain information about density distributions of upper mantle and lithosphere structures. A gravity profile is most often a combination of relatively sharp anomalies that must be of shallow origin and very deep and large anomalies with a regional nature. The study profile has a 400 (km) length from SW to NE of North Western Iran, and Sahand, North Tabriz Fault, and Sabalan are the most important structures in the study area. The Normalized Full Gradient synthetic model data study provides the opportunity for the real data recovered model judgment. So, we first showed the Normalized Full Gradient recovered model of the synthetic data test and then based on the resolution of the Normalized Full Gradient used, it provides the lithospheric density of North Western Iran. The result shows the low-density mantle wedge which is probably is beneath the North Tabriz Fault that is responsible for the formation of distinct lithosphere conditions. So, the wedge can explain the complicated tectonic setting of North Western Iran. The mantle wedge has more than 50 (km) wide and more than 40 (km) depth. seemingly, this mantle wedge directly affects the North Tabriz Fault, Sahand, and Sabalan in the shallower depth. The sharpest effect is for the North Tabriz Fault in the shallower part of the mantle wedge and following the shape of the wedge, we can see a sharper effect on the Sabalan in comparison with Sahand. [ABSTRACT FROM AUTHOR]

Purpose: One of the most important risks of organizations is technology risk. In gas companies, due to the expansion of activities, increase in the number of subscribers, and increase share of gas in energy basket, technology has a very important role in delivering appropriate service. Risk assessment in gas technology development projects is very vital. In fact, the existence of numerous risks in the gas industry is one of the main obstacles to the technology development in the country's gas industry. In other words, the implementation of plans and projects of the gas industry are highly risky due to the uncertainty of the specific elements of this industry. The purpose of this study is to provide a suitable framework for identifying and ranking the risks of gas companies using the integrative technique of FMEA and TOPSIS. The distinguished aspect of this paper compared to previous studies is the new method developed based on failure modes and effects analysis (FMEA), Shannon Entropy approach, and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) for ranking technological risks of the gas company. Design/methodology/approach: In this paper, technology risks in gas distribution have been determined based on literature and expert’s viewpoints. Then, the identified risks were sent to 33 of the company's experts via the FMEA worksheet. After rating the risks by the experts in the FMEA worksheet, instead of obtaining the Risk Priority Number (RPN) number for each risk, the risks were prioritized using the TOPSIS technique. The FMEA method considers three kinds of attributes, namely, occurrence, detection rate, and severity. Occurrence is the probability of the risk, detection rate is the ability of detecting risk, and severity is applied as severity of the effect of risk. The judgment about determination of indicators has been proposed by experts. In this paper, TOPSIS has been used instead of applying an RPN to assess potential failure modes by multiplying indicators of occurrence, detection rate, and severity. TOPSIS is a ranking method with the aim of selecting alternatives that simultaneously have the shortest and farthest distances from the positive and negative ideal solutions, respectively. Findings: Findings indicated that the most important technology risks in gas distribution are i) variation in macroeconomics index (exchange and inflation rate) in country; ii) inability to access required equipment and machinery; iii) inability to access manufacturing technologies; and iv) limited financing for technology development. Research limitations/implications: One of the limitations of this study was separate access to the projects of this industry. In this study, the gas distribution project was defined generally and included all projects in the gas distribution industry. In fact, it was not possible to individually access the gas distribution projects. Analyzing and presenting solutions for each risk separately was another limitation of this study. In other words, considering each risk separately according to the structure of the industry was another limitation of this study. Practical implications: The results were valid based on the reasonable method and experts’ confirmation and could be suitable for this industry. The technique presented in this study was based on information obtained from the Chaharmahal and Bakhtiari Province Gas Company, while due to the similar structure of provincial gas companies in gas technology and distribution, the method and results obtained in this study can be applied in all gas companies in the field of gas distribution. Social implications: The results of this study could decrease the cost of gas distribution industry by determining the most important technological risks of the gas company. Originality/value: The aim of this study was to propose a new method of FMEA for ranking technological risks of the gas company by integrating Shannon Entropy approach and TOPSIS. The contribution of this study was the investigation of the technological risks of the gas company. In addition, in this paper, a new method was applied by the integration of FMEA and TOPSIS. [ABSTRACT FROM AUTHOR]

1- Introduction In recent decades, countries around the world have thought about using clean energy carriers as a solution for problems caused by excessive air and environmental pollution. Meanwhile, natural gas consumption has been increased due to less diffusion of carbon dioxide (compared to other fossil fuels) and more environmental sustainability it can cause thus, demand for it has risen to the utmost degree. Iran owns 18% of world total gas reserves which makes it the second-biggest gas owner in the world. Thus, this country can play a prominent role in answering the increased demand for gas in the new atmosphere mentioned above and this can add to its geopolitical prominence. However, in spite of various potential benefits of natural gas for Iran, due to existing challenges, this country has not been able to use its opportunities. In the current research, we study Iran's challenges and opportunities with respect to natural gas, from a geopolitical perspective. 2- Research Method This study has been conducted through using analytical descriptive method. Considering the nature of the studied subject, the needed data has been gathered by using library resources. 3- Discussion With regard to gas reserves, Iran is a very rich country, and by having 29.61 trillion cubic meters of exploitable gas reserves- which consists of 15.8% of proven gas reserves of the world- it has the second-largest gas reserves in the world after Russia. More than half of Iran's gas reserves are located in common gas fields and more than two-thirds of them are placed in non-associated gas fields. Iran's the most important non-associated gas fields are: South Pars, North Pars, Nar, Khangiran. Most of Iran's gas reserves are in southern areas of the country, near Persian Gulf, and many of them are jointly owned by Iran and its neighboring countries. The largest of them is South Pars field that holds half of Iran's gas reserves. Compared to its huge gas reserves and its rank in the world in that respect, Iran's gas production is far less than expected. However, in recent years, an increase in gas production can be witnessed, the amount of which has been 131.2 billion cubic meters in 2009. This amount has been 4.4% of total amount of worldwide gas production and makes Iran the fourth-biggest producer of gas in the world. Concerning gas consumption, in 1993, Iran has consumed 26.6 billion cubic meters of natural gas which has risen to 131.7 billion cubic meters in 2009. These figures show that in 16 years, the amount of gas production in Iran has increased five times. So, we can see that Iran's huge gas reserves pose their own challenges for the country, the most important of which is excessive consumption of natural gas. 4- Conclusion Iran has the second-largest gas reserves in the world. However, this country is facing significant challenges in this respect, the most important of which are excessive consumption of natural gas, common gas fields, amount of burnt gases, and sanctions encouraged by the US and the opposition of that country to the development of Iran's gas sector. These sanctions have caused foreign companies not to invest in Iranian gas market, and thus, Iran's natural gas sector has a lower development rate compared to other gas owners in the world. However, this sector can offer great opportunities for Iran and it can be a base for the development of the country. By exporting gas and changing it into materials with higher added value, Iran's financial development can be accelerated. We should consider that gas is the main fuel used by Iranian petrochemical industries. Furthermore, transferring gas through pipelines to other countries and the resulting long-term contracts can improve Iran's financial and political relationship with other countries. Through this, Iran can reach out to Asian and European regions and by providing gas for them, Iran can increase its national security. This can be achieved through objection of these countries to any kind of sanction or threat imposed against Iran. In other words, Iran's geopolitical and strategic position, combined with its huge gas reserves, can help Iran reach out to international gas markets, which can increase Iran's economic and political power. In addition to that, gas injection to Iran's oil reservoirs can improve recycling and production of oil, the economic benefits of which are more than gas exportation at the moment. Furthermore, by adding to the number of gas-burning vehicles, Iran can reduce the amount of its imported petrol, which is considered as Iran's Achilles' heel in west's view. Iran is facing de facto challenges in natural gas sector which have brought about considerable harms for the country. But its opportunities in this sector are still untapped and for realizing them, Iran should first face the challenges and then solve them. [ABSTRACT FROM AUTHOR]

Background: Existence of coordinated and professional safety system to prevent occurrence of accidents and potential hazards seem to be essential in installing networks of gas distribution projects. Objective: To survey work-related accidents and safety performance indices in project implementation unit of Yazd gas agency. Methods: This analytical study was conducted on 197 of workforce in Yazd gas agency in 2013 that were selected by census and they were male. Demographic and accident information were gathered using a self-made questionnaire and face- to- face interview, and required information obtained from dossier to determine the safety performance indicators. Safety performance indicators were calculated in separately of 13 types occupations in project implementation unit of gas agency and data were analyzed using T-test. Findings: The highest accident frequency and severity rate were related to digging occupation and then metal line welding. Consequences of accidents were cuts (%56.7) and soreness (%14.9). The causes of accidents were related to uselessness of personal protective equipment (%25.2) and lack of precision in the task (%19.3). The highest rate of accident was observed among the age group 20-29 years with work experience of 4-6 years. Conclusion: According to the findings of this study and the risk of gas processes, it seems to be necessary the implementation of integrated management systems and training of workers about safety rules to improve the safety culture and prevent accidents.

Background: South Pars gas field is the world's largest gas field and the capital of energy in Iran. The oil and gas industry exerts potential effects on the health and culture of its surrounding community. The sustainability requirements of development projects include local participation, human sustainability and social sustainability. The present study was conducted to investigate health-associated challenges and their effective causes and solutions from the perspective of the residents of the camps and the staff of Pars Special Economic Energy Zone (PSEEZ) as stakeholders and participants in the development projects. Materials and Methods: The present qualitative study was conducted on a population comprising two groups, including the staff of the region’s industry and the residents of camps. Purposive sampling was used to collect data using four methods, including library studies, holding group discussion sessions and surveying the staff, ethnographic observations and focus group discussion. The data were collected from the questions raised and content analysis was performed. Results: Inadequate living facilities and space, insufficient facilities for recreation and exercise, failing to comply with health standards and requirements, addition and psychological illnesses were proposed as the main problems in the region. The solutions proposed by the employees in the region included planning and enforcing its implementation, forcing employers to meet the minimum health standards, financing or attracting investments for recreational and welfare facilities and teaching safety precautions and health points to the residents and employees. Conclusion: The root cause of the problems is mainly operational and structural. Most of the solutions are therefore compulsory, including obligations such as forcing contractors to meet the requirements, changing welfare regulations and following a legally-enforced program. [ABSTRACT FROM AUTHOR]