Barge-Assisted Draft Reduction of Semi-Submersible Drilling Unit GSF Development Driller I for Tow-Out From Ingleside to Offshore Gulf of Mexico

2007 ◽  
Author(s):  
Frank van Hoorn ◽  
Warren Weaver ◽  
James N. Brekke ◽  
S. Douglas Devoy
Keyword(s):  
Gulf Of Mexico ◽  
Time Domain ◽  
Ground Clearance ◽  
Drilling Rig ◽  
Domain Motion ◽  
Drilling Unit ◽  
Reasonable Ground ◽  
Favorable Weather

Because of its DP thrusters, the free-floating draft of the semi-submersible drilling rig GSF Development Driller I was too deep for a safe tow-out from Ingleside, TX, to open waters. In order to reduce the semi’s draft, a large cargo barge was used to lift the rig 1.0 m (3.3 ft) and thus create a reasonable ground clearance. The barge was selected, based on dimension, ballast capability, deck strength, price, and availability. Eight support brackets were welded to the barge sides and strong diaphragms welded inside the four rig braces. Detailed time domain motion analyses were performed to study the behavior of the combined units during the tow and barge removal operation offshore. In April of 2006, during a favorable weather window, the combined units were successfully towed through the channels and once in deeper waters, the barge was ballasted down and pulled out from under the rig.

First Application Drilling New Wells with HWU in Swamp Environment, Mahakam Delta

2021 ◽  
Author(s):  
R. A. S Wijaya
Keyword(s):  
Drilling Rate ◽  
Shallow Gas ◽  
Field Development ◽  
Drilling Rig ◽  
East Kalimantan ◽  
Well Location ◽  
Shallow Wells ◽  
Drilling Unit ◽  
Mature Field ◽  
Mahakam Delta

Tunu is a mature giant gas and condensate field locate in Swamp Area on Mahakam Delta, East Kalimantan, Indonesia. The field has been in developed for more than 40 years and considered as a mature field. As mature field, finding an economic well has become more challenging nowadays. The deeper zone of Tunu (TMZ) has no longer been considered profitable to be produced and the focus is shifted more on the producing widespread shallow gas pocket located in the much shallower zone of Tunu (TSZ). Facing the challenge of marginal reserves in the mature field, Pertamina Hulu Mahakam (PHM) take two approaches of reducing well cost thus increase well economics, improving drilling efficiency and alternative drilling means. Continues improvement on drilling efficiency by batch drilling, maxi drill, maximizing offline activities and industrialization of one phase well architecture has significantly squeezed the well duration. The last achievement is completing shallow well in 2.125 days from average of 6.5 days in period of 2017-2019. Utilization of Swamp Barge Drilling Rig on swamp area had been started from the beginning of the field development in 1980. Having both lighter and smaller drilling unit as alternative drilling means will give opportunity of reducing daily drilling rate. Hydraulic Workover Unit (HWU) comes as the best alternative drilling means for swamp area. In addition, fewer and smaller footprint equipment requires smaller barges with purpose of less civil works to dredge the river and preparing well location. Drilling with HWU project has been implemented at Tunu area with 5 wells has been completed successfully and safely. HWU drilling concept considered as proven alternative drilling means for the future of shallow wells development.

FHS Semi: A Semisubmersible Design for Dry Tree Applications

2009 ◽  
Author(s):  
Alaa M. Mansour
Keyword(s):  
Gulf Of Mexico ◽  
Water Depth ◽  
Time Domain ◽  
Frequency Range ◽  
Integration Technique ◽  
Natural Period ◽  
Ballast Tank ◽  
New Feature ◽  
Fully Coupled

In this paper the performance of a new conceptual semisubmersible design that provides motion response similar to a Spar is investigated. The new invention introduces a new feature which is the Free-Hanging Solid Ballast Tank, hence the name FHS Semi. The use of the free-hanging Solid Ballast Tank (SBT) significantly increases the heave natural period while controlling the heave response in the wave frequency range and, therefore, enables the use of the FHS Semi in dry tree applications. The new design’s quayside integration technique and its interface with the top tensioned risers are presented in this paper. Case study for the new design to support a 32,000 ST payload including 15 Top Tensioned Risers (TTRs) in an ultra-deepwater of 8,000 ft water depth is considered. Frequency domain and fully coupled time-domain hydrodynamic analyses have been performed and numerical results are presented to illustrate the new semisubmersible design response in extreme Gulf of Mexico hurricane events.

Robustness of an SCR in Gulf of Mexico Hurricane Conditions

2010 ◽  
Author(s):  
Partha Sharma ◽  
Kim Mo̸rk ◽  
Vigleik Hansen ◽  
Celso Raposo ◽  
Srinivas Vishnubhotla
Keyword(s):  
Gulf Of Mexico ◽  
Time Domain ◽  
Offshore Structures ◽  
Coupled Analysis ◽  
Floating Structure ◽  
Steel Catenary Riser ◽  
Strength Capacity ◽  
Critical Components ◽  
Robustness Check ◽  
Robustness Assessment

Recent hurricanes in Gulf of Mexico, most notably Ivan (2004), Katrina & Rita (2005), Ike (2008), were more severe than the local 100 year extremes in the Gulf of Mexico (GoM). As a result API has issued an interim metocean bulletin, API Bulletin 2INT-MET [1]. Concurrently, API also issued API Bulletin 2INT-EX [2] for assessment of existing offshore structures for hurricane conditions. API Bulletin 2INT-EX recommends a robustness check to evaluate floating structure critical components including production and export risers. The robustness check for risers as a minimum should consider the capacity and ductility of the key riser components. This paper investigates the robustness of a steel catenary riser (SCR) suspended from a deepwater tension leg platform (TLP) unit in Central GoM. The robustness assessment is performed for the 1000 year Central GoM hurricane conditions provided in API 2INT-MET. Time domain coupled analysis using the program DeepC is performed to determine the TLP motions and the associated loading on the SCR. SCR strength capacity checks are performed as per the methods outlined in new ISO 13628-12 [3].

The Effect of Mooring Line Pre-Tension on FDPSO’s Motion

2016 ◽  
Author(s):  
Yanlong Sun ◽  
Huilong Ren ◽  
Zhendong Liu ◽  
Liu Yan ◽  
Zepeng Guo
Keyword(s):  
Time Series ◽  
Model Test ◽  
Time Domain ◽  
Prediction Method ◽  
Line Tension ◽  
Mooring Line ◽  
Floating Platform ◽  
Motion Response ◽  
Drilling Unit ◽  
Environment Condition

As a multifunction floating platform, Floating Drilling, Production, Storage and Offloading (FDPSO) combining the well-known Floating Production, Storage and Offloading (FPSO) with a drilling unit. For the environment condition of deep-water oilfield is very severe, the motion response and mooring line tension of FDPSO is a worthy topic of studying. In this study, the numerical time-domain coupled prediction method for the mooring line tension and motion response of FDPSO system is constructed by ANSYS AQWA software. Furthermore, the results of a model test conducted in Harbin Engimeering University are used to investigate the feasibility and validity of the commercial simulation. The effect of mooring line pre-tension on the response of FDPSO is studied by varying the pre-tension of mooring line during the calculation. The time series curve of the mooring line tension and motion response, and the comparison of motion spectrum and mooring line tension spectrum are provided in this article.

Estimate of Fuel Consumption of a DP System on FPSO

2014 ◽  
Author(s):  
José Manuel Cabrera Miranda ◽  
Rafael Corona Tapia
Keyword(s):  
Gulf Of Mexico ◽  
Fuel Consumption ◽  
Time Domain ◽  
Heavy Oil ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Statistical Information ◽  
Calculation Procedure ◽  
Well Testing ◽  
Offshore Development

The Pemex Ayatsil-Tekel offshore development is located 120 km northeast from Ciudad del Carmen, México in the Gulf of México on 1100 km2 area. Due to the extra-heavy oil nature of the reservoirs, a DP-FPSO will be mobilized across different fields for execution of Extended Well Testing (EWT). Several oil samples will be taken along periods of up to 12 months for each well without interruption. The aim of this work is to determine a first good estimate of the DP system fuel consumption, which is of interest for budgetary purposes of the operator. The calculation procedure considers statistical information of winds, currents and waves from scatter diagrams of the region. It is assumed that the FPSO has weathervane capabilities and thus only head environmental forces are calculated. A first estimate of fuel consumption will be confirmed after FPSO contract is awarded and a more accurate time domain analysis is performed.

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