Innovative Approach to Drilling Across Highly Fractured Formation in the Biggest Deep Gas Field in the Middle East

2021 ◽  
Author(s):  
Efe Mulumba Ovwigho
Keyword(s):  
Risk Assessment ◽  
Middle East ◽  
Current Drive ◽  
Successful Implementation ◽  
Prevention Measures ◽  
Gas Field ◽  
Time Saving ◽  
Well Control ◽  
Carbonate Formation ◽  
Open Hole

Abstract On a Deep Gas Field in the Middle East, it is required to drill across a highly fractured and faulted carbonate formation. In most wells drilled across the flank of this field, it is impossible to cure the encountered losses with conventional or engineered solutions. Average time to cure losses is 20 days. With the current drive for cost optimization, it has become necessary to eliminate the NPT associated with curing the losses. A thorough risk assessment was conducted for wells drilled on the flank of this field, it was established that the risk of encountering total losses was very high. Seismic studies were performed and it was observed it would be impossible to eliminate total losses as fractures were propagated in all directions. It was proposed to run a sacrificial open hole bridge plug above the loss zone and sidetrack the well instead of performing extensive remedial operations. The proposed solution would help eliminate the well control and HSE risks associated with drilling blindly ahead with the reservoir formation exposed. Applied the proposed solution on the next well that was drilled on the flank of the field, encountered total losses, spotted eight LCM pills, unable to cure the losses, ran sacrificial open hole bridge plug and sidetracked the well. The entire process was completed in 30 hours. Sidetracked the well in adjacent direction to the initial planned well trajectory based on further seismic data analysis and no losses was encountered. Recovered full mud column to surface thus ensuring the restoration of all well barrier elements. This solution has since been adopted as best practice for wells drilled on the flank of the field where there is high probability of encountering total losses. The average time saving per well due to this optimized solution is 450 hours for wells where total losses are encountered. This engineered solution has made drilling wells on the flank of the field in a timely manner possible and at optimized costs. This has resulted in: –The elimination of Non-Productive Time,–Quick delivery of the well to production,–Reduced HSE risk,–Reduced well control risk as loss zone is quickly isolated before drilling ahead. This paper will explain why running sacrificial open hole bridge plugs and sidetracking the well is a more effective solution compared to extended remedial operations when total losses are encountered while drilling across highly fractured / faulted formation. It will discuss the extensive risk assessment conducted, the mitigation and prevention measures that were put in place in order to ensure successful implementation on trial well.

Engineered Composite Lost Circulation Solution to Successfully Cure Total Losses During Drilling Across Naturally Fractured Formations in Ghawar Gas Field, Saudi Arabia

2021 ◽  
Author(s):  
Faizan Ahmed Siddiqi ◽  
Carlos Arturo Banos Caballero ◽  
Fabricio Moretti ◽  
Mohamed AlMahroos ◽  
Uttam Aswal ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Circulation System ◽  
Cement Slurry ◽  
Fiber System ◽  
Gas Field ◽  
Well Control ◽  
Lost Circulation ◽  
Carbonate Formation ◽  
Naturally Fractured ◽  
Zonal Isolation

Abstract Lost circulation is one of the major challenges while drilling oil and gas wells across the world. It not only results in nonproductive time and additional costs, but also poses well control risk while drilling and can be detrimental to zonal isolation after the cementing operation. In Ghawar Gas field of Saudi Arabia, lost circulation across some naturally fractured formations is a key risk as it results in immediate drilling problems such as well control, formation pack-off and stuck pipe. In addition, it can lead to poor isolation of hydrocarbon-bearing zones that can result in sustained casing pressure over the life cycle of the well. A decision flowchart has been developed to combat losses across these natural fractures while drilling, but there is no single solution that has a high success rate in curing the losses and regaining returns. Multiple conventional lost circulation material pills, conventional cement plugs, diesel-oil-bentonite-cement slurries, gravel packs, and reactive pills have been tried on different wells, but the probability of curing the losses is quite low. The success with these methods has been sporadic and shown poor repeatability, so the need of an engineered approach to mitigate losses is imperative. An engineered composite lost-circulation solution was designed and pumped to regain the returns successfully after total losses across two different formations on a gas well in Ghawar field. Multiple types of lost-circulation material were tried on this well; however, all was lost to the naturally fractured carbonate formation. Therefore, a lost-circulation solution was proposed that included a fiber-based lost-circulation control (FBLC) pill, composed of a viscosifier, optimized solid package and engineered fiber system, followed by a thixotropic cement slurry. The approach was to pump these fluids in a fluid train so the FBLC pill formed a barrier at the face of the formation while the thixotropic cement slurry formed a rapid gel and quickly set after the placement to minimize the risk of losing all the fluids to the formation. Once this solution was executed, it helped to regain fluid returns successfully across one of the naturally fractured zones. Later, total losses were encountered again across a deeper loss zone that were also cured using this novel approach. The implementation of this lost-circulation system on two occasions in different formations has proven its applicability in different conditions and can be developed into a standard engineered approach for curing losses. It has greatly helped to build confidence with the client, as it contributed towards minimizing non-productive time, mitigated the risk of well control, and assisted in avoiding any remedial cementing operations that may have developed due to poor zonal isolation across certain critical flow zones.

scholarly journals A Methodology for Harmonizing Safety and Health Scales in Occupational Risk Assessment

2021 ◽  
Vol 18 (9) ◽  
pp. 4849
Author(s):  
Zuzhen Ji ◽  
Dirk Pons ◽  
John Pearse
Keyword(s):  
Risk Assessment ◽  
Health And Safety ◽  
Assessment Method ◽  
Assessment Process ◽  
Successful Implementation ◽  
Health Issues ◽  
Public Health Perspective ◽  
Chronic Health ◽  
Risk Assessment Method

Successful implementation of Health and Safety (H&S) systems requires an effective mechanism to assess risk. Existing methods focus primarily on measuring the safety aspect; the risk of an accident is determined based on the product of severity of consequence and likelihood of the incident arising. The health component, i.e., chronic harm, is more difficult to assess. Partially, this is due to both consequences and the likelihood of health issues, which may be indeterminate. There is a need to develop a quantitative risk measurement for H&S risk management and with better representation for chronic health issues. The present paper has approached this from a different direction, by adopting a public health perspective of quality of life. We have then changed the risk assessment process to accommodate this. This was then applied to a case study. The case study showed that merely including the chronic harm scales appeared to be sufficient to elicit a more detailed consideration of hazards for chronic harm. This suggests that people are not insensitive to chronic harm hazards, but benefit from having a framework in which to communicate them. A method has been devised to harmonize safety and harm risk assessments. The result was a comprehensive risk assessment method with consideration of safety accidents and chronic health issues. This has the potential to benefit industry by making chronic harm more visible and hence more preventable.

scholarly journals Geochemical Mapping, Risk Assessment, and Source Identification of Heavy Metals in Road Dust Using Positive Matrix Factorization (PMF)

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 614
Author(s):  
Muhammad Faisal ◽  
Zening Wu ◽  
Huiliang Wang ◽  
Zafar Hussain ◽  
Chenyang Shen
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Matrix Factorization ◽  
Anthropogenic Activities ◽  
Contamination Factor ◽  
Road Dust ◽  
Positive Matrix Factorization ◽  
Prevention Measures ◽  
Positive Matrix ◽  
The City

Heavy metals in road dust pose a significant threat to human health. This study investigated the concentrations, patterns, and sources of eight hazardous heavy metals (Cr, Ni, Cu, Zn, As, Cd, Pb, and Hg) in the street dust of Zhengzhou city of PR China. Fifty-eight samples of road dust were analyzed based on three methods of risk assessment, i.e., Geo-Accumulation Index (Igeo), Potential Ecological Risk Assessment (RI), and Nemerow Synthetic Pollution Index (PIN). The results exhibited higher concentrations of Hg and Cd 14 and 7 times higher than their background values, respectively. Igeo showed the risks of contamination in a range of unpolluted (Cr, Ni) to strongly polluted (Hg and Cd) categories. RI came up with the contamination ranges from low (Cr, Ni, Cu, Zn, As, and Pb) to extreme (Cd and Hg) risk of contamination. The risk of contamination based on PIN was from safe (Cu, As, and Pb) to seriously high (Cd and Hg). The results yielded by PIN indicated the extreme risk of Cd and Hg in the city. Positive Matrix Factorization was used to identify the sources of contamination. Factor 1 (vehicular exhaust), Factor 2 (coal combustion), Factor 3 (metal industry), and Factor 4 (anthropogenic activities), respectively, contributed 14.63%, 35.34%, 36.14%, and 13.87% of total heavy metal pollution. Metal’s presence in the dust is a direct health risk for humans and warrants immediate and effective pollution control and prevention measures in the city.

Strategies to Promote the Safety of Vulnerable Road Users in Developing and Emerging Countries: South African Experience

2003 ◽  
Vol 1846 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Hubrecht Ribbens
Keyword(s):  
South Africa ◽  
Middle East ◽  
The United States ◽  
Emerging Countries ◽  
Sub Saharan Africa ◽  
Successful Implementation ◽  
Road Traffic Safety ◽  
Road Users ◽  
Vulnerable Road Users ◽  
The Caribbean

Road casualties are discussed from a worldwide perspective. More than 80% of annual traffic casualties occur in developing and emerging countries in Asia, Latin America, the Caribbean, sub-Saharan Africa, and the Middle East. Vulnerable road users such as pedestrians and bicyclists are a major road safety problem in these countries. In Asia, Africa, the Caribbean, and the Middle East, more than 40% of annual road fatalities involve pedestrians compared with less than 20% in Europe and the United States. The focus of this study is South Africa’s strategy to promote the safety of vulnerable road users. The extent of casualties among vulnerable road users and contributing factors are highlighted. Over the last decade, pedestrian fatalities have gradually and steadily declined in South Africa. This study describes the various policies, strategies, and action plans developed and implemented by different government levels in South Africa to promote road traffic safety, particularly the safety of vulnerable road users such as pedestrians and bicyclists. Barriers to successful implementation are also pointed out. Apart from applying a holistic approach by involving all relevant disciplines, a coordinated and sustained effort of all government levels was encouraged. Joint-venture funding projects among different government levels was emphasized to improve hazardous pedestrian locations. The role of the private sector in South Africa to promote pedestrian safety is also discussed. Practical guidelines are presented for developing and emerging countries to promote the safety of vulnerable road users.

Failure Analysis of the Tripping Operation and its Impact on Well Control

2015 ◽  
Author(s):  
Majeed Abimbola ◽  
Faisal Khan ◽  
Vikram Garaniya ◽  
Stephen Butt
Keyword(s):  
Human Error ◽  
Integrated Control ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Well Control ◽  
Lost Circulation ◽  
Critical Elements ◽  
Open Hole ◽  
Critical Components ◽  
The Cost

As the cost of drilling and completion of offshore well is soaring, efforts are required for better well planning. Safety is to be given the highest priority over all other aspects of well planning. Among different element of drilling, well control is one of the most critical components for the safety of the operation, employees and the environment. Primary well control is ensured by keeping the hydrostatic pressure of the mud above the pore pressure across an open hole section. A loss of well control implies an influx of formation fluid into the wellbore which can culminate to a blowout if uncontrollable. Among the factors that contribute to a blowout are: stuck pipe, casing failure, swabbing, cementing, equipment failure and drilling into other well. Swabbing often occurs during tripping out of an open hole. In this study, investigations of the effects of tripping operation on primary well control are conducted. Failure scenarios of tripping operations in conventional overbalanced drilling and managed pressure drilling are studied using fault tree analysis. These scenarios are subsequently mapped into Bayesian Networks to overcome fault tree modelling limitations such s dependability assessment and common cause failure. The analysis of the BN models identified RCD failure, BHP reduction due to insufficient mud density and lost circulation, DAPC integrated control system, DAPC choke manifold, DAPC back pressure pump, and human error as critical elements in the loss of well control through tripping out operation.

Challenging Catenary Coiled Tubing Thru Tubing Screen Deployment Operation Offshore Borneo

2021 ◽  
Author(s):  
Seng Wei Jong ◽  
Yee Tzen Yong ◽  
Yusri Azizan ◽  
Richard Hampson ◽  
Rudzaifi Adizamri Hj Abd Rani ◽  
...  
Keyword(s):  
Oil Wells ◽  
Well Control ◽  
Coiled Tubing ◽  
Open Hole ◽  
Catenary System ◽  
Offshore Oil ◽  
Gravel Pack ◽  
Emergency Measures

Abstract Production decline caused by sand ingress was observed on 2 offshore oil wells in Brunei waters. Both wells were completed with a sub-horizontal openhole gravel pack and were subsequently shut in as the produced sand would likely cause damage to the surface facilities. In an offshore environment with limited workspace, crane capacity and wells with low reservoir pressures, it was decided to intervene the wells using a catenary coiled tubing (CT) vessel. The intervention required was to clean out the sand build up in the wells and install thru-tubing (TT) sand screens along the entire gravel packed screen section. Nitrified clean out was necessary due to low reservoir pressures while using a specialized jetting nozzle to optimize turbulence and lift along the deviated section. In addition, a knockout pot was utilized to filter and accommodate the large quantity of sand returned. The long sections of screens required could not be accommodated inside the PCE stack resulting in the need for the operation to be conducted as an open hole deployment using nippleless plug and fluid weight as well control barrier. A portable modular crane was also installed to assist the deployment of long screen sections prior to RIH with CT. Further challenges that needed to be addressed were the emergency measures. As the operation was to be conducted using the catenary system, the requirement for an emergency disconnect between the vessel and platform during the long cleanout operations and open hole deployment needed to be considered as a necessary contingency. Additional shear seal BOPs, and emergency deployment bars were also prepared to ensure that the operation could be conducted safely and successfully.

scholarly journals A pandemic risk assessment of middle east respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia

2017 ◽  
Vol 24 (7) ◽  
pp. 1631-1638 ◽  
Author(s):  
Saleh A. Eifan ◽  
Islam Nour ◽  
Atif Hanif ◽  
Abdelrahman M.M. Zamzam ◽  
Sameera Mohammed AlJohani
Keyword(s):  
Risk Assessment ◽  
Saudi Arabia ◽  
Middle East ◽  
Middle East Respiratory Syndrome

scholarly journals Cardiovascular risk assessment in South and Middle-East Asians living in the Western countries

2020 ◽  
Vol 36 (7) ◽  
Author(s):  
Sahrai Saeed ◽  
Alka M Kanaya ◽  
Louise Bennet ◽  
Peter M Nilsson
Keyword(s):  
Risk Assessment ◽  
Cardiovascular Risk ◽  
Middle East ◽  
South Asian ◽  
South Asians ◽  
Middle Eastern ◽  
Cardiovascular Risk Assessment ◽  
The West ◽  
East Asians ◽  
Western Countries

Nearly a quarter of the world population lives in the South Asian region (India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan, and the Maldives). Due to rapid demographic and epidemiological transition in these countries, the burden of non-communicable diseases is growing, which is a serious public health concern. Particularly, the prevalence of pre-diabetes, diabetes and atherosclerotic cardiovascular disease (CVD) is increasing. South Asians living in the West have also substantially higher risk of CVD and mortality compared with white Europeans and Americans. Further, as a result of global displacement over the past three decades, Middle-Eastern immigrants now represent the largest group of non-European immigrants in Northern Europe. This vulnerable population has been less studied. Hence, the aim of the present review was to address cardiovascular risk assessment in South Asians (primarily people from India, Pakistan and Bangladesh), and Middle-East Asians living in Western countries compared with whites (Caucasians) and present results from some major intervention studies. A systematic search was conducted in PubMed to identify major cardiovascular health studies of South Asian and Middle-Eastern populations living in the West, relevant for this review. Results indicated an increased risk of CVD. In conclusion, both South Asian and Middle-Eastern populations living in the West carry significantly higher risk of diabetes and CVD compared with native white Europeans. Lifestyle interventions have been shown to have beneficial effects in terms of reduction in the risk of diabetes by increasing insulin sensitivity, weight loss as well as better glycemic and lipid control. doi: https://doi.org/10.12669/pjms.36.7.3292 How to cite this:Saeed S, Kanaya AM, Bennet L, Nilsson PM. Cardiovascular risk assessment in South and Middle-East Asians living in the Western countries. Pak J Med Sci. 2020;36(7):---------. doi: https://doi.org/10.12669/pjms.36.7.3292 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

scholarly journals Quantitative Risk assessment of product disulfide bond reduction in a recombinant protein manufacturing

2021 ◽  
Author(s):  
Yi Qing cui ◽  
rujie meng ◽  
yutong Li
Keyword(s):  
Risk Assessment ◽  
Cell Culture ◽  
Recombinant Protein ◽  
Disulfide Bond ◽  
Culture Fluid ◽  
Culture Conditions ◽  
Quantitative Risk Assessment ◽  
Prevention Measures ◽  
Recombinant Molecule ◽  
Disulfide Bond Reduction

Disulfide bond reduction occurred now and then during a recombinant protein manufacturing. Their reduction often led in the loss of batches. Various prevention measures were developed. Their implementation in a manufacturing inevitably increases its operation complexity and even might impact its product qualities and process performances. It is highly desirable to apply a reduction measure only if necessary and to apply no strong measure if a moderate one works. The reduction occurrence is determined both by the reduction sensitivity of a recombinant molecule and by the reduction power of harvested cell culture fluids. The reduction power of harvested cell culture fluids varies largely and depends on cells, lysis level, growth stage, and culture conditions. The method of the quantitative risk assessment of disulfide bond reduction was reported here. The quantitative assessment is realized by comparing the reduction sensitivity of a recombinant molecule with the reduction power of its harvested cell culture fluid.

scholarly journals epiflows: an R package for risk assessment of travel-related spread of disease

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1374 ◽  
Author(s):  
Paula Moraga ◽  
Ilaria Dorigatti ◽  
Zhian N. Kamvar ◽  
Pawel Piatkowski ◽  
Salla E. Toikkanen ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Length Of Stay ◽  
R Package ◽  
International Travel ◽  
Population Movement ◽  
Cumulative Number ◽  
Prevention Measures ◽  
Expected Number ◽  
Source Of Infection ◽  
Asymptomatic Infections

As international travel increases worldwide, new surveillance tools are needed to help identify locations where diseases are most likely to be spread and prevention measures need to be implemented. In this paper we present epiflows, an R package for risk assessment of travel-related spread of disease. epiflows produces estimates of the expected number of symptomatic and/or asymptomatic infections that could be introduced to other locations from the source of infection. Estimates (average and confidence intervals) of the number of infections introduced elsewhere are obtained by integrating data on the cumulative number of cases reported, population movement, length of stay and information on the distributions of the incubation and infectious periods of the disease. The package also provides tools for geocoding and visualization. We illustrate the use of epiflows by assessing the risk of travel-related spread of yellow fever cases in Southeast Brazil in December 2016 to May 2017.

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