Integrated wellbore-quality and risk-assessment study guides successful drilling in Amazon jungle

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. E99-E105 ◽  
Author(s):  
Azra N. Tutuncu ◽  
Mikhail Geilikman ◽  
Brent Couzens ◽  
Floris van Duyvenboode
Keyword(s):  
Risk Assessment ◽  
Trajectory Optimization ◽  
Horizontal Stress ◽  
Rock Properties ◽  
Borehole Stability ◽  
Hole Cleaning ◽  
Lost Circulation ◽  
Assessment Study ◽  
Well Design ◽  
Fracture Gradient

Significant lost-circulation and wellbore-instability problems in the form of bit balling, stuck pipe, and adverse mud-shale interactions have been experienced in wells drilled prior to the study at three prospects in the Amazon jungle. An integrated borehole-stability and risk-assessment study has been carried out to enable successful drilling by optimizing borehole fluid pressures and predicting safe openhole times in various troublesome zones. The guidelines for hole-cleaning parameters and well-trajectory optimization have been obtained using improved fracture gradient and horizontal stress-anisotropy proprietary models based on special drill-cuttings data. Monopole and dipole sonic and imaging logs along with drilling data from the prospect wellshave been used to determine in-situ stresses, rock properties, andformation strength. These parameters have been utilized in borehole stability, hole cleaning, and open-hole time analyses for a comprehensive risk assessment and for selection of the optimum wellpath and drilling design. The wellbore pressures required for borehole stability turned out to be the highest for vertical wells and lowest for the horizontal ones, making drilling of highly deviated and horizontal wells attractive for the prospects. As a result, a wellpath with high deviation in the direction of maximum horizontal stress has been recommended as the most stable choice. The recommendations have been incorporated in the well design and implemented in the field with real-time borehole stability monitoring to result in successful drilling and efficient project economics.

scholarly journals Integrated mechanical earth model and quantitative risk assessment to successful drilling

2020 ◽  
Author(s):  
Alireza Noohnejad ◽  
Kaveh Ahangari ◽  
Kamran Goshtasbi
Keyword(s):  
Risk Assessment ◽  
Sensitivity Analysis ◽  
Stochastic Approach ◽  
Horizontal Stress ◽  
Wellbore Stability ◽  
Quantitative Risk Assessment ◽  
Earth Model ◽  
Calibration Data ◽  
Lost Circulation ◽  
Weight Window

Abstract Use of vital geomechanical parameters for determination of safe mud pressure window is generally associated with high level of uncertainty primarily because of absence of sufficient calibration data including laboratory and field test information. The traditional deterministic wellbore stability analysis methodologies usually overlooked the uncertainty of these key parameters. This paper exhibits implementing a quantitative risk assessment technique on the basis of Monte-Carlo modeling to consider uncertainty from input data so as to make it possible to survey not just the likelihood of accomplishing a desired level of wellbore stability at a particular mud weight, but also the impacts of the uncertainty in each single parameter on the wellbore stability. This methodology was implemented to a case study. The most important parameters have been recognized using a sensitivity analysis approach in which the outcome of this QRA procedure suggests the mud weight window with likelihood of well drilling success which can elude the wellbore collapse and lost circulation events. This sort of stochastic approach to deal with anticipated safe mud weight window can guarantee stable wellbore with considerable cost viability associated with drilling success. The technique built up in this paper can give the scientific foundation for assessment of wellbore stability under complicated geological circumstances. It was likewise noted that based on sensitivity analysis, uniaxial compressive strength and maximum horizontal stress are the most effective parameter in estimation of mud weight window. This accentuates the significance of trustworthy determinations of these two parameters for safe drilling of the future wells in the field.

Field Application of Software Model and Wellbore Strengthening Materials for Drilling Depleted Reservoirs and Mechanically Weak Formations in Gulf of Suez

2021 ◽  
Author(s):  
Youssry Abd El-Aziz Mohamed ◽  
Ragab Saber Ahmed ◽  
Ayman Abd El-ghany Al-Zahry ◽  
Amr Ismail Moustafa ◽  
Radi Ahmed Elnashar ◽  
...  
Keyword(s):  
Field Application ◽  
Rock Properties ◽  
Software Model ◽  
Software Models ◽  
Well Design ◽  
Wellbore Pressure ◽  
Drilling Operations ◽  
Wellbore Strengthening ◽  
Fracture Gradient ◽  
Selection Of

Abstract Drilling operations might require increasing mud weight beyond formation's fracture gradient margin which may lead to downhole losses into formation and other potential problems resulting in Non-Productive Time (NPT). This paper describes successful application of wellbore strengthening software (WSS) to simulate formations’ strengthening process by increasing Hoop Stress while drilling depleted reservoir sand or mechanically weak formations. The software model takes into consideration well design, basic rock properties and in-situ earth stresses. The paper also defines design of mud formula and lab procedures verifying the designed wellbore strengthening materials (WSM) blend and successful application in field. Design and selection of mud formula are main pillars of successful formation strengthening procedure to match with induced fractures width. Unlike other software models that use generic particle size distribution (PSD) data, software in this study takes into consideration PSD of specific batches of WSM to simulate wellbore strengthening process and recommend the optimum WSM blend, concentrations. Based on mud formula design from WSS, lab tests were conducted to verify concentrations and selection of WSM and accordingly formulas were applied successfully for complicated drilling operations. Static and dynamic formation strengthening techniques were applied successfully in multiple wells. Based on software results and recommendations, Techniques’ application managed to strengthen weak formations up to 121% of original fracture gradient, decreased section drilling time by 20% which resulted in drilling costs reduction by up to 24.2 %. As a result of this successful application in many critical wells, WSS results are now integral to operator's well plan to enhance wellbore pressure integrity of weak intervals, in following drilling operations. The presented study is based on an innovative approach to strengthen weak and depleted formations in critical drilling operations using exact PSD data of WSM batches, formation properties and customized software model, an optimum concentrations blend can be selected to strengthen wellbore and hence it can be customized for every application where optimum formation strengthening is required.

scholarly journals The chemical composition and heavy metal content of sesame oil produced by different methods: A risk assessment study

2021 ◽  
Author(s):  
Somayeh Kheirati Rounizi ◽  
Fateme Akrami Mohajeri ◽  
Hamdollah Moshtaghi Broujeni ◽  
Fatemeh Pourramezani ◽  
Sara Jambarsang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Heavy Metal ◽  
Chemical Composition ◽  
Metal Content ◽  
Sesame Oil ◽  
Heavy Metal Content ◽  
Assessment Study

scholarly journals Bio-engineered palladium nanoparticles: model for risk assessment study of automotive particulate pollution on macrophage cell lines

RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1850-1861
Author(s):  
Aarzoo ◽  
Saba Naqvi ◽  
Nidhi Bharal Agarwal ◽  
Manoj P. Singh ◽  
M. Samim
Keyword(s):  
Risk Assessment ◽  
Cell Lines ◽  
Palladium Nanoparticles ◽  
Macrophage Cell ◽  
Particulate Pollution ◽  
Assessment Study

The surge in vehicular activity in densely populated areas has led to an increased concentration of airborne palladium nanoparticles (PdNPs) in the environment.

Wellhead Design Enables Offline Cementing and a Shift in Operational Efficiency

2021 ◽  
Vol 73 (05) ◽  
pp. 68-69
Author(s):  
Chris Carpenter
Keyword(s):  
Oil And Gas ◽  
Operational Efficiency ◽  
Asia Pacific ◽  
Significant Shift ◽  
Lost Circulation ◽  
Well Design ◽  
Geological Conditions ◽  
The Moment ◽  
Tubing Hanger ◽  
Column Pressure

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202439, “Pushing Malaysia’s Drilling Industry Into a New Frontier: How a Distinctive Wellhead Design Enabled Implementation of a Fully Offline Well Cementing Resulting in a Significant Shift in Operational Efficiency,” by Fauzi Abbas and Azrynizam M. Nor, Vestigo, and Daryl Chang, Cameron, a Schlumberger Company, prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Traditionally, rigs are positioned over a well from the moment the surface casing is drilled until the installation of the wellhead tree. This results in the loss of precious time as the rig idles during online cementing. However, in mature Field A offshore Terengganu, Malaysia, a new approach eliminated such inefficiency dramatically. Operational Planning With oil production in Field A initiated in October 2015, historical data on well lithology, formation pressure, and potential issues during drilling were available and were studied to ensure that wells would not experience lost circulation. This preplanning is crucial to ensure that the offline cementing activity meets the operator’s barrier requirements. Petronas Procedures and Guidelines for Upstream Activities (PPGUA 4.0) was used for the development of five subject wells in Field A. In this standard, two well barriers are required during all well activities, including for suspended wells, to prevent uncontrolled outflow from the well to the external environment. For Field A, two barrier types, mechanical and fluid, allowed by PPGUA 4.0 were selected to complement the field’s geological conditions. As defined in PPGUA 4.0, the fluid barrier is the hydrostatic column pressure, which exceeds the flow zone pore pressure, while the mechanical barrier is an element that achieves sealing in the wellbore, such as plugs. The fluid barrier was used because the wells in Field A were not known to have circulation losses. For the development of Field A, the selected rig featured a light-duty crane to assist with equipment spotting on the platform. Once barriers and rig selection are finalized, planning out the drill sequence for rig skidding is imperative. Space required by drillers, cementers, and equipment are among the considerations that affect rig-skid sequence, as well as the necessity of increased manpower. Offline Cementing Equipment and Application In Field A, the casing program was 9⅝×7×3½ in. with a slimhole well design. The wellhead used was a monobore wellhead system with quick connectors. The standard 11-in. nominal wellhead design was used for the wells with no modifications required. All three sections of the casing program were offline cemented. They were the 9⅝-in. surface casing, 7-in. production casing, and 3½-in. tubing. The 9⅝-in. surface casing is threaded to the wellhead housing and was run and landed with the last casing joint. Subsequent wellhead 7-in. casing hangers and a 3½-in. tubing hanger then were run and landed into the compact housing.

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