scholarly journals Modelling and variability of selected chemical properties of shallow water wells using GIS in Wasit and Dhi Qar provinces/Iraq

2020 ◽  
Vol 39 (1) ◽  
pp. 13-26
Author(s):  
Basima Abbas Jabir Al-humairi ◽  
◽  
Nadhum Shamkhi Rahal ◽  
Ahmed Kareem Jebur ◽  
◽  
...  
Keyword(s):  
Shallow Water ◽  
Chemical Properties ◽  
Water Wells

Optimisation of Conductor System Design to Minimise Wellhead Fatigue Issues

2013 ◽  
Author(s):  
Dara Williams ◽  
Kevin Purcell
Keyword(s):  
System Design ◽  
Shallow Water ◽  
Water Depth ◽  
Fatigue Loading ◽  
Recent Experience ◽  
Water Wells ◽  
Increased Risk ◽  
Main Driver ◽  
Drilling Rigs ◽  
Water Depths

Current market trends in the construction of newbuild drilling rigs indicate that the market is driven by demand for ultra-deepwater capacity semi-submersible rigs and drillships. These drilling vessels have capacity to drill in water depths of up to 12,000ft and possibly beyond in the near future. With increase in water depth capacity, more complex and heavier BOP stacks are required. Many modern drilling vessels are now incorporating BOPs with capacities of 20ksi pressure and up to 7 shear/seal rams incorporated. This leads to increased height and weight in the BOP. Whilst newbuild drilling vessels will be required to operate in water depths from 1,500ft to 12,000ft whilst on DP mode, deepwater semi-submersible drilling rigs will also have capability for operation in water depths <1,500ft using conventional mooring. Recent experience with modern deepwater rigs with large BOP stacks in water depth of 1,500ft or less suggests increased risk of fatigue when compared to 3rd generation rigs. If future trends continue with larger BOP stacks being designed then the problem of wellhead fatigue with modern deepwater drilling vessels is likely to become more acute. As noted in previous studies the water depth at drillsite has a major impact on the level of fatigue accumulated in the wellhead system. The main driver for this has been found to be the height and weight of the BOP. With requirements for newbuild drilling rigs for 12,000ft water depth capacity being the industry norm, and with increased requirements for BOP functionality, the gap between wellhead loading from 3rd generation and 6th generation rigs is widening. Given that many 3rd generation rigs will likely be decommissioned in the coming years then the usage of 6th generation rigs for shallow water operations will only become more commonplace due to rig availability. Thus, unless market conditions dictate the construction of smaller and lighter BOP stacks, the design of shallow water wells will be critical to ensure fatigue loading on the wellhead and conductor is kept to a minimum. This paper presents a summary of the results of a series of parameter studies carried out to assess a range of options for optimisation of casing and conductor design for 6th generation rigs in shallow water. Various recommendations are made as part of this study as to the addition of supplemental casing and conductor strings of varying sizes and wall thickness to ensure a robust conductor system design for fatigue performance.

scholarly journals Mycology of Hand-dug Shallow Water Wells in Awka Metropolis, Anambra State, Nigeria

2016 ◽  
Vol 4 (2) ◽  
pp. 17-22
Author(s):  
Onuorah Samuel ◽  
Elesia Rosemary ◽  
Odibo Frederick
Keyword(s):  
Shallow Water ◽  
Anambra State ◽  
Water Wells

scholarly journals Hydrochemical Assessment of Groundwater and Some Springs in Qazaniyah Area, Diyala province, East of Iraq

2020 ◽  
pp. 2277-2292
Author(s):  
Haider N. Fakhre ◽  
Firas Mudhafar Abdulhussein
Keyword(s):  
Calcium Chloride ◽  
Chemical Properties ◽  
High Hardness ◽  
World Health ◽  
Dry Period ◽  
Water Wells ◽  
Health Organization ◽  
Physical And Chemical ◽  
Very High ◽  
And Chemical Properties

The Qazaniyah study included the analysis of 18 wells and 2 springs for the dry period in October 2018 and the wet period in April 2019, including the analysis of physical and chemical properties and the study of heavy elements (Fe, Zn, Cd, Pb, Ni and Cu).The results showed that the water wells and springs for the two periods are highly mineralized and characterized by low alkalinity and very high hardness. Water was fresh in some wells and salty in the others, whereas it was fresh in the springs. Most  of the wells had sodium chloride type, except the wells 12, 7, 6, and 5 which were of Calcium chloride type. The springs for both seasons had calcium chloride type. Based on the World Health Organization criteria ,  all the wells for both periods are not suitable for human drinking, whereas the springs are suitable only for drinking of livestock and poultry. Sodium adsorption rate (SAR) was excellent for groundwater and springs for both seasons. The percentage of sodium  (na%) in both seasons showed that the wells 18,17,15,11,4,3 as well as the springs are within the permissible limits for irrigation purposes, while the remaining of the wells was not.

Structural Integrity Assurance for Corroded Conductors in Offshore Shallow-Water Wells

2018 ◽  
Author(s):  
Oleksandr Spuskanyuk ◽  
Saad Mumtaz ◽  
Amr Mahmoud ◽  
Chee Lam Gan ◽  
Walid M. Abdulhai ◽  
...  
Keyword(s):  
Shallow Water ◽  
Structural Integrity ◽  
Water Wells ◽  
Integrity Assurance

Operational Challenges for Drilling Shallow Water Wells With Dynamically Positioned Rigs

2020 ◽  
Author(s):  
Rohit Vaidya ◽  
Mahesh Sonawane
Keyword(s):  
Shallow Water ◽  
Weak Link ◽  
Mitigation Options ◽  
Drilling Rig ◽  
Water Wells ◽  
Fatigue Monitoring ◽  
Drilling Operations ◽  
Drilling Rigs ◽  
New Generation ◽  
Selection Of

Abstract Traditionally, shallow water wells have been drilled from fixed platforms, jack-ups or moored drilling rigs. Recently there has been increased interest in performing operations on these wells using new generation of Dynamically Positioned (DP) rigs, driven by available capacity of these rigs and environmental regulations that restrict laying anchors on the seabed. Shallow water offshore drilling operations present a set of unique challenges and these challenges are further amplified when operations are performed on older wells with legacy conductor hardware with newer DP vessels and larger BOPs. The objective of the paper is to present challenges that occur during drilling in shallow water and discuss mitigation options to make these operations feasible through a series of case studies. Key challenges to optimizing riser operability and rig uptime are discussed. Potential modifications to the upper riser stack-up and rig deck structure for maximizing operational uptime are discussed. Riser system weak point assessment is presented along with solutions for mitigating risks in case the wellhead or conductor structural pipe is identified as the weak link. Selection of the drilling rig can have significant impact on wellhead fatigue response. Some criteria for rig selection based on drilling riser and wellhead system performance is presented with the objective of optimizing the fatigue performance of the wellhead and conductor system. Wellhead fatigue monitoring solutions in combination with physical fatigue mitigation options are presented to enable operations for fatigue critical wells.

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