scholarly journals Analytical Study of Early Kick Detection and Well Control Considerations for Casing while Drilling Technology

2021 ◽  
Author(s):  
M Azab
Keyword(s):  
Drill Pipe ◽  
Drill String ◽  
Wellbore Stability ◽  
Well Control ◽  
Lost Circulation ◽  
Drilling Technique ◽  
Drilling Technology ◽  
Drilling Operations ◽  
Fracture Gradient ◽  
Conventional Drilling

Abstract Recently, casing while drilling (CwD) technology has been employed to reduce drilling time and expenses. These intelligent drilling technique improved wellbore stability, fracture gradient, and formation damage while reducing exposure time but when a well control issue arises, the differences in wellbore geometries and related volumes compared to regular conventional drilling procedures necessitate a distinct strategy. In this paper, the essential well control parameters were provided for casing while drilling operations, presents simplified method that has been developed to evaluate the maximum kick tolerance (KT) for both conventional and casing while drilling techniques using a mathematical derivation, the narrow annular clearance, in contrast to drilling with a conventional drill string would impair kick detection and handling operations. Furthermore, the large disparity in kick tolerances should be carefully evaluated in order to avoid lost circulation/kick cycles as well as examine and evaluate technical approaches to early kick detection (EKD) studying how they relate to safety, efficiency, and reliability in a variety of common casing while drilling operations. According to preliminary findings, by utilizing casing while drilling technology and compared to identical well was drilled conventionally using drill pipe, the annulus pressure loss (APL) is average 3 times of the conventional drilling technique. Furthermore, kick tolerance is reduced by 50% and maximum allowable well shut-in time reduced by 65% necessitating early kick detection.

Wellbore Geomechanics of Extended Drilling Margin and Engineered Lost-Circulation Solutions

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1178-1188 ◽  
Author(s):  
Amin Mehrabian ◽  
Younane Abousleiman
Keyword(s):  
Mechanical Properties ◽  
Stability Analysis ◽  
Analytical Approach ◽  
Wellbore Stability ◽  
Tensile Failure ◽  
Mechanical Interaction ◽  
Lost Circulation ◽  
Drilling Operations ◽  
Secondary Fractures ◽  
Lost Circulation Materials

Summary Wellbore tensile failure is a known consequence of drilling with excessive mud weight, which can cause costly events of lost circulation. Despite the successful use of lost-circulation materials (LCMs) in treating lost-circulation events of the drilling operations, extensions of wellbore-stability models to the case of a fractured and LCM-treated wellbore have not been published. This paper presents an extension of the conventional wellbore-stability analysis to such circumstances. The proposed wellbore geomechanics solution revisits the criteria for breakdown of a fractured wellbore to identify an extended margin for the equivalent circulation density (ECD) of drilling. An analytical approach is taken to solve for the related multiscale and nonlinear problem of the three-way mechanical interaction between the wellbore, fracture wings, and LCM aggregate. The criteria for unstable propagation of existing near-wellbore fractures, together with those for initiating secondary fractures from the wellbore, are obtained. Results suggest that, in many circumstances, the occurrence of both incidents can be prevented, if the LCM blend is properly engineered to recover certain depositional and mechanical properties at downhole conditions. Under such optimal design conditions, the maximum ECD to which the breakdown limit of a permeable formation could be enhanced is predicted.

Wellbore Shielding Technique Increases Operative Window, Avoiding Formation Instability and Losses, Minimizing NPT, and Optimizing Drilling Operations in the Unconventional Plays

2021 ◽  
Author(s):  
Gaston Lopez ◽  
Gonzalo Vidal ◽  
Claus Hedegaard ◽  
Reinaldo Maldonado
Keyword(s):  
Drilling Fluid ◽  
Drilling Fluids ◽  
Wellbore Instability ◽  
Lost Circulation ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Vaca Muerta ◽  
Drilling Operations ◽  
Fracture Gradient ◽  
Vaca Muerta Formation

Abstract Losses, wellbore instability, and influxes during drillings operations in unconventional fields result from continuous reactivity to the drilling fluid causing instability in the microfractured limestone of the Quintuco Formation in Argentina. This volatile situation becomes more critical when drilling operations are navigating horizontally through the Vaca Muerta Formation, a bituminous marlstone with a higher density than the Quintuco Formation. Controlling drilling fluids invasion between the communicating microfractures and connecting pores helps to minimize seepage losses, total losses, wellbore fluid influxes, and instabilities, reducing the non-productive time (NPT) caused by these problems during drilling operations. The use of conventional sealants – like calcium carbonate, graphite, asphalt, and other bridging materials – does not guarantee problem-free drilling operations. Also, lost circulation material (LCM) is restricted because the MWD-LWD tools clearances are very narrow in these slim holes. The challenge is to generate a strong and resistant seal separating the drilling fluid and the formation. Using an ultra-low-invasion technology will increase the operative fracture gradient window, avoid fluid invasion to the formation, minimize losses, and stop the cycle of fluid invasion and instability, allowing operations to maintain the designed drilling parameters and objectives safely. The ultra-low-invasion wellbore shielding technology has been applied in various fields, resulting in significantly improved drilling efficiencies compared to offset wells. The operator has benefited from the minimization of drilling fluids costs and optimization in drilling operations, including reducing the volume of oil-based drilling fluids used per well, fewer casing sections, and fewer requirements for cementing intervals to solve lost circulation problems. This paper will discuss the design of the ultra-low-invasion technology in an oil-based drilling fluid, the strategy for determining the technical limits for application, the evaluation of the operative window with an increase in the fracture gradient, the optimized drilling performance, and reduction in costs, including the elimination of NPT caused by wellbore instability.

Development of DNN Model for Predicting Surge Pressure Gradient During Tripping Operations

2020 ◽  
pp. 294-315
Author(s):  
Shwetank Krishna ◽  
Syahrir Ridha ◽  
Pandian Vasant
Keyword(s):  
Machine Learning ◽  
Deep Neural Network ◽  
Drill String ◽  
Analytical Models ◽  
Learning Tools ◽  
Well Control ◽  
Step Process ◽  
Well Integrity ◽  
Drilling Operations ◽  
Applications Of Machine Learning

Application of machine learning tools in drilling hydrocarbon well is still exploratory in its stage. This chapter presents a brief review of various applied research in drilling operations using machine learning (ML) tools and develop a deep neural network (DNN) model for predicting the downhole pressure surges while tripping. Tripping in or out drill-string/casing with a certain speed from the wellbore will result in downhole pressure surges. These surges could result in well integrity or well control problems, which can be avoided if pressure imbalances are predicted before this operation is engaged. Existing analytical models focus on forecasting the pressure imbalance but requires cumbersome numerical analysis. This could be solved by integrating DNN tool with the best existing analytical model predicted dataset. Consequently, the aim of this chapter is to provide an overview of various applications of machine learning tools in drilling and presenting a step-by-step process of developing a DNN model for the prediction of downhole pressure surges during tripping operation.

Casing Point Selection for Drilling Operations at Shallow Depths

2009 ◽  
Author(s):  
Amir Saman Paknejad ◽  
Jerome J. Schubert ◽  
Mahmood Amani
Keyword(s):  
Design Method ◽  
Cost Optimization ◽  
Elastic Behavior ◽  
Plastic Behavior ◽  
Point Selection ◽  
Well Control ◽  
Lost Circulation ◽  
Fracture Pressure ◽  
Drilling Operations ◽  
Shallow Sediments

In shallow sediments, unlike deep sediments with elastic behavior, the failure mechanism of the casing shoe is strongly affected by the plasticity of the rock. Hence, the common practice in casing design which is based on using the pore pressure and fracture pressure gradients plots is not applicable in shallow sediments. Moreover, because of the plastic behavior of the sediments, the interpretation of Leak-Off Tests (LOT) in Shallow Marine Sediments (SMS) could be inconclusive. Therefore, because of uncertainties in prediction of formation fracture and pore gradients, the conductor and surface casing setting depths have always been subject to debate. Also, incorrect interpretation of LOT would lead to costly problems that might jeopardize well progress such as; well control issues, unnecessary squeeze jobs, premature setting of casing, and lost circulation problems. Two of the most important factors in any design are safety and cost. Since safety is one of the most important concerns during drilling an offshore well, planning a design based on the well control aspects would be an appropriate approach to come up with a safe and better design. A well control simulator was used to plan for well control situations. In this paper, the results were generalized for different design scenarios and a simple design method is presented. Also, a new method, supported by field data from LOT in SMS, is presented to accurately analyze casing shoe leak-off pressure in the SMS. A safe design based on the optimum lengths of conductor and surface casing would enable the operator to handle possible formation kicks. Extension of this method to well design in general suggests the potential for safer drilling operations and cost optimization.

Fit for Purpose Connection Design for Drilling Operations in Size Constrained Tubular

2021 ◽  
Author(s):  
Guillaume Plessis ◽  
Andrei Muradov ◽  
Richard Griffin ◽  
Jeremy Dugas ◽  
Justin Orlando ◽  
...  
Keyword(s):  
Drill Pipe ◽  
Drill String ◽  
Internal Diameter ◽  
Engineering Technology ◽  
Technology Center ◽  
Drilling Operations ◽  
Fit For Purpose ◽  
The One ◽  
Connection Design ◽  
Outside Diameter

Abstract Drilling out or working within small sizes of casing and liners requires the use of a drill string with small outside diameter tool joints to fit inside the casing/liner bore and, at the same time, a large enough connection internal diameter to pump actuating balls inside the drill string when needed. These requirements significantly limit the available options that can be used. Historically, a drill pipe double shoulder connection with a 3⅛-in. outside diameter (OD) has been used for such operations, as it allows for multiple makeups and breakouts before it needs to be repaired. This is a great improvement compared to using small tubing premium connections that are somewhat limited on the number of makeups. However, the geometry constraints are such that the thin material envelope leads to torsional weakness in the connection, resulting in a higher than expected recut rate as connections can be overtorqued downhole in operation. A research and development (R&D) project was commissioned to improve the connection performance significantly to mitigate the downhole overtorque. Exploring the acceptable connection envelope limits allowed for a slightly reduced internal diameter (ID) when compared to the previously used connection. The team considered different thread designs and decided to use the one that would provide the highest torque. The design process was then followed to develop and qualify a well-balanced connection. The design validation was performed at an engineering technology center in Houston, Texas, where samples were destructively tested to compare the actual capacity of the new connection against the calculated values. It was confirmed that the torsional strength of the new design meets and exceeds the theoretical value, an improvement of at least 85% over the previously used connection, and a first string was built. It was subsequently deployed in the field and the recut rate was monitored to establish that the objective of delivering a connection capable of higher torque was indeed met to resist the downhole overtorque.

Redefining Technical Limit – Managed Pressure Directional Drilling Solution in Mexico Homol Field

2021 ◽  
Author(s):  
J. L. Lopez Mata ◽  
S.. Perez ◽  
H. H. Vizcarra ◽  
Alex Ngan ◽  
E. A. Garcia Gil ◽  
...  
Keyword(s):  
Communication Protocol ◽  
Wellbore Stability ◽  
Plastic Behavior ◽  
Directional Drilling ◽  
Wellbore Instability ◽  
Well Control ◽  
Drilling Performance ◽  
Innovative Solution ◽  
Drilling Technology ◽  
History Of

Abstract This paper will discuss the Managed Pressure Directional Drilling fit-for-purpose solution deployed to meet drilling challenges in Mexico's offshore Homol field. This innovative solution integrates a new state-of-the-art Rotary Steerable System (RSS) with Managed Pressure Drilling (MPD) technology. Drilling hazards such as the ballooning effect due to drilling plastic formations, losses, wellbore instability, and stuck pipe were effectively mitigated, and improved drilling performance with reduced NPT was delivered compared to other directional drilling systems. The solution requires the integration of two highly technical disciplines, MPD and Directional Drilling. Hence, a Joint Operating & Reporting Procedure (JORP) and a defined communication protocol proved crucial for effective execution. The solution is based on a rigorous Drilling Engineering process, including detailed offset well analysis to deliver a comprehensive risk assessment and mitigation plan jointly with the Operator to tackle drilling hazards such as ballooning without compromising the directional drilling requirements. In addition, flow processes and procedures were developed for contingency events, including but not limited to losses, stuck pipe, wellbore instability, and well control. After successfully deploying the new RSS tool in Mexico offshore, the Operator came across a challenging directional well with a history of ballooning effect, losses, stuck pipe, and wellbore instability. Combining the RSS tool with MPD Constant Bottom Hole Pressure (CBHP) technique to mitigating the ballooning effect while maintaining constant surface back pressure (SBP), the well was drilled while minimizing the downhole pressure fluctuation to mitigate against wellbore instability until reaching the lower paleocene formation, taking care to maintain an equivalent circulating density (ECD) of 2.04g/cc while drilling, and 1.99g/cc during connections, in order to reduce the ballooning effect observed in offset wells. As a result of careful planning, the RSS and downhole-surface communication continued to work well, while the MPD CBHP variant successfully mitigated against ballooning and well control hazards. The paper will also discuss the effective communication protocol between directional drilling, MPD services, and rig contractors to ensure safe operational alignment. Rotary steerable systems (RSS) for directional drilling must drill in increasingly hostile environments and with different challenges inherent to formations; examples of this are formations with plastic behavior that cause ballooning effect. This phenomenon can confuse drilling crew cause its behavior is very similar to kicks from wells. Homol is an oilfield with marked ballooning characteristics, causing significant Non-Productive Time (NPT). Drilling challenges in the Homol field require the utilization of both Directional Drilling technology and MPD techniques to improve drilling performance and reduce NPT at the same time. However, the technologies need to be optimized for one another. Also, directional services had to ensure reliability and accurately position wells, while the MPD technology to discern ballooning from actual influx and managing wellbore stability. This article describes the teamwork carried out by the directional team and MPD to avoid/minimize the ballooning effect while drilling directional jobs, improving operational time. The paper also includes a planning and operational blueprint to reduce NPT related to, while increasing drilling performance in terms of rate of penetration (ROP) and wellbore quality to allow the liner to be run to section TD in the Lower Paleocene formation.

Improved Drilling Operations with Wired Drill Pipe and Along-String Measurements – Learnings and Highlights from Multiple North Sea Deployments

2021 ◽  
Author(s):  
Børge Engdal Nygård ◽  
Espen Andreassen ◽  
Jørn Andre Carlsen ◽  
Gunn Åshild Ulfsnes ◽  
Steinar Øksenvåg ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Real Time ◽  
High Speed ◽  
Drill Pipe ◽  
Large Data ◽  
Drill String ◽  
Bottom Hole Assembly ◽  
Drilling Operations ◽  
Downhole Measurements ◽  
Remote Operations

Abstract Over the last few years, multiple wells have been drilled in the Norwegian Continental Shelf (NCS) and the United Kingdom Continental Shelf (UKCS) using wired drill pipe (WDP). This paper captures highlights from using real-time downhole measurements provided by WDP, for improved drilling operations. It presents learnings on how WDP measurements have been used in the operator's decision process. As part of WDP, along-string measurement subs (ASM) are equipped with temperature, annular/internal pressure, rotation and vibrations sensors. Data is transmitted to surface at high speed and is available in real-time, even when flow is off. The data provide great insight into the hole conditions along the drill string and at the bottom hole assembly (BHA). Based on this insight, drilling parameters at surface can be accurately adjusted, resulting in increased overall efficiency. Large data amounts can be communicated to and from surface with negligible time delay and independent from fluid circulation. Displaying the downhole measurements in real-time, both at the rig site and in remote operations centers has proven essential when optimising well construction activities. All parties need to access the same information in real-time. Moreover, the data need to be presented in an intuitive manner that enable improved operational decisions. To maximize WDP values, the Operator has learned that downhole data must be used to adjust drilling operations in real-time.

Mitigating Lost Circulation Across Permeable Formations of the Gunashli Field in the Caspian Sea with a New Tailored Spacer System

2021 ◽  
Author(s):  
Tom Farrow ◽  
Nurlan Gadimov ◽  
Kyriacos Agapiou ◽  
Mukhtar Safarov
Keyword(s):  
Caspian Sea ◽  
Field Application ◽  
Wellbore Stability ◽  
The Caspian Sea ◽  
Lost Circulation ◽  
History Of ◽  
Drilling Operations ◽  
Zonal Isolation ◽  
Additional Costs ◽  
Loss Control

Abstract Cementing operations seek to minimize non-productive time (NPT) as part of the broad effort to optimize costs. A commonly encountered event that contributes to NPT is lost circulation. Lost circulation may often be associated, and treated, during drilling operations, but can occur during cementing practices, e.g. while running casing in the wellbore and/or circulating cement and treatment fluids. When fluids are lost to the formation and not appropriately cured, cementing objectives may not be met and, ultimately, zonal isolation can be compromised. Additional costs may be incurred to remediate the well construction and achieve a dependable barrier. It is, therefore, of great interest to develop and implement solutions which can facilitate the prevention and treatment of lost circulation. Described herein is the evaluation and use of a new tailored spacer system (TSS) engineered to effectively prevent lost circulation and maintain wellbore stability. The TSS was designed for use in cementing shallow water Caspian Sea wells with permeable formations and a history of losses. The spacer was subjected to conventional spacer tests and simulations including rheological measurements, compatibility assessments and fluid modeling to ensure job requirements would be met. Loss control tests were performed to verify the efficacy of the TSS to effectively prevent losses. All screenings demonstrated the TSS would be well-suited for the intended field application. The spacer system was successfully deployed in Caspian Sea wells and helped meet cementing objectives where conventional treatments failed.

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