Best Practice to Improve Slim Hole Maximum Reservoir Contact Well Drilling Performance

2021 ◽  
Author(s):  
Rodrigo Antillon Moreira ◽  
Ramanujan Jeughale ◽  
Toki Takahiro ◽  
Toma Motohiro ◽  
Kerron Andrews ◽  
...  
Keyword(s):  
Friction Factor ◽  
Best Practice ◽  
Drilling Fluid ◽  
Stock Selection ◽  
Well Drilling ◽  
Drilling Performance ◽  
Well Integrity ◽  
Drilling Parameters ◽  
Open Hole ◽  
Extended Reach Drilling

Abstract Reservoir sections in MRC (Maximum Reservoir Contact) & ERD (Extended Reach Drilling) wells are mainly designed to drill 8 ½" hole, because of drilling limitations with smaller hole size. However, slim hole sizes offer opportunities to revitalize existing wells using re-entry drilling techniques in association with MRC and ERD designs. This paper discusses the best practices to be implemented in order to mitigate risk, reduce complexity and ensure improved drilling performance. Re-Entry wells in the field have a risk of well integrity issues such as corroded 9 5/8" casing. In order to mitigate this risk, the corroded 9 5/8" casing should be covered by 7" liner & tied-back to surface before drilling reservoir section. In this situation up to 18,000 ft of 4" DP is used in the wells to drill 6" hole and run 4 ½" lower completion. Offset well analysis, whip stock selection criteria, BHA design, drilling fluid selection, drilling and tripping practices based on torque & drag and hydraulics calculations are most important to achieve the well objective. The Slim hole MRC well was completed without any issues and achieved good drilling performance. It was observed that the actual drilling parameters such as torque, drag and stand pipe pressure were less than simulated parameters. NAF was selected in the section to reduce the friction factor, while motorized RSS and a reamer stabilizer were used in the BHA to reduce torque, drag and ensure a smooth well profile. A back reaming practice was implemented in hole section to reduce dog leg severity and the open hole was eventually displaced to viscosified brine to minimize the friction factor for running the 4 ½' lower completion. 8500 ft of 6" hole section was drilled and TD was reached at +/- 19,000ft within 50 days including recovering the existing completion, drilling 8 ½" & 6" hole and running completion. This paper aims to contribute to the oilfield industry by sharing the successfully implemented engineering design and operation execution methodology to overcome the complexities present in Re Entry Wells MRC/ERD wells required to be drilled with slim hole conditions under an optimal cost, time effectiveness and low risk.

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.

Drilling System Optimization Leads to Expedited Wells Delivery

2021 ◽  
Author(s):  
Efe Mulumba Ovwigho ◽  
Saleh Al Marri ◽  
Abdulaziz Al Hajri
Keyword(s):  
Drill Pipe ◽  
System Optimization ◽  
Drill String ◽  
Stick Slip ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Single String ◽  
Innovative Solution ◽  
Open Hole ◽  
Weight On Bit

Abstract On a Deep Gas Project in the Middle East, it is required to drill 3500 ft of 8-3/8" deviated section and land the well across highly interbedded and abrasive sandstone formations with compressive strength of 15 - 35 kpsi. While drilling this section, the drill string was constantly stalling and as such could not optimize drilling parameters. Due to the resulting low ROP, it was necessary to optimize the Drill string in order to enhance performance. Performed dynamic BHA modelling which showed current drill string was not optimized for drilling long curved sections. Simulation showed high buckling levels across the 4" drill pipe and not all the weight applied on surface was transmitted to the bit. The drilling torque, flowrate and standpipe pressures were limited by the 4" drill pipe. This impacted the ROP and overall drilling performance. Proposed to replace the 4" drill pipe with 5-1/2" drill pipe. Ran the simulations and the model predicted improved drill string stability, better transmission of weights to the bit and increased ROP. One well was assigned for the implementation. Ran the optimized BHA solution, able to apply the maximum surface weight on bit recommended by the bit manufacturer, while drilling did not observe string stalling or erratic torque. There was also low levels of shocks and vibrations and stick-slip. Doubled the on-bottom ROP while drilling this section with the same bit. Unlike wells drilled with the previous BHA, on this run, observed high BHA stability while drilling, hole was in great shape while POOH to the shoe after drilling the section, there were no tight spots recorded while tripping and this resulted in the elimination of the planned wiper trip. Decision taken to perform open hole logging operation on cable and subsequently run 7-in liner without performing a reaming trip. This BHA has been adopted on the Project and subsequent wells drilled with this single string showed similar performance. This solution has led to average savings of approximately 120 hours per well drilled subsequently on this field. This consist of 80 hours due to improved ROP, 10 hrs due to the elimination of wiper trip and a further 30 hrs from optimized logging operation on cable. In addition, wells are now delivered earlier due to this innovative solution. This paper will show how simple changes in drill string design can lead to huge savings in this current climate where there is a constant push for reduction in well times, well costs and improved well delivery. It will explain the step-by-step process that was followed prior to implementing this innovative solution.

Real Time Automation of Cutting Carrying Capacity Index to Predict Hole Cleaning Efficiency and Thereby Improve Well Drilling Performance

2021 ◽  
Author(s):  
Mohammed M Al-Rubaii ◽  
Dhafer Al-Shehri ◽  
Mohamed N Mahmoud ◽  
Saleh M Al-Harbi ◽  
Khaled A Al-Qahtani
Keyword(s):  
Real Time ◽  
Carrying Capacity ◽  
Drilling Fluid ◽  
Model Development ◽  
Cleaning Efficiency ◽  
Time Model ◽  
Well Drilling ◽  
Hole Cleaning ◽  
Drilling Performance ◽  
Drilling Operations

Abstract Hole cleaning efficiency is one of the major factors that affects well drilling performance. Rate of penetration (ROP) is highly dependent on hole cleaning efficiency. Hole cleaning performance can be monitored in real-time in order to make sure drilled cuttings generated are efficiently transported to surface. The objective of this paper to present a real time automated model to obtain hole cleaning efficiency and thus effectively adjust parameters as required to improve drilling performance. The process adopts a modified real time carrying capacity indicator. There are many hole cleaning models, methodologies, chemicals and correlations, but majority of these models do not simulate drilling operations sequences and are not dependent on practicality of drilling operations. The developed real time hole cleaning indicator can ensure continuous monitoring and evaluation of hole cleaning performance during drilling operations. The methodology of real time model development is by selecting offset mechanical drilling parameters and drilling fluid parameters where collected, analyzed, tested and validated to model strong hole cleaning efficiency indicator that can extremely participate and facilitate a position in drilling automations and fourth industry revolution. The automated hole cleaning model is utilizing real time sensors of drilling and validate the strongest relationships among the variables. The study, analysis, test and validation of the relationships will reveal the significant parameters that will contribute massively for model development procedures. The model can be run as well by using the real time sensors readings and their inputs to be fed into the developed automated model. The developed model of real time carrying capacity indicator profile will be shown as function of depth, drilling fluid density, flow rate of mud pump or mud pump output, and other important factors will be illustrated by details. The model has been developed and validated in the field of drilling operations to empower the drilling teams for better and understandable monitoring and evaluation of hole cleaning efficiency while performing drilling operations. The real time model can provide a vision for better control of mud additives and that will contribute to mud cost effectiveness. The automated model of hole cleaning efficiency optimized the rate of penetration (ROP) by 50% in well drilling performance as a noticeable and valuable improvement. This optimum improvement saved cost and time of rig and drilling of wells and contributed to accelerate wells’ delivery. The innovative real time model was developed to optimize drilling and operations efficiency by using the surface rig sensors and interpret the downhole measurements and that can lead innovatively to other important hole cleaning indicators and other tactics for better development of downhole measurements models that can participate for optimized drilling efficiency.

Enabling Extended Reach Wells with the Aid of an Ultra-High Speed Rotational Reamer Shoe

2021 ◽  
Author(s):  
Manchukarn Naknaka ◽  
Chimere Nkwocha ◽  
Pattarapong Prasongtham ◽  
Tossapol Tongkum ◽  
Trinh Dinh Phu ◽  
...  
Keyword(s):  
High Speed ◽  
Drilling Fluid ◽  
Gulf Of Thailand ◽  
Integrity Test ◽  
Lost Circulation ◽  
Ultra High Speed ◽  
Open Hole ◽  
The Gulf Of Thailand ◽  
Difficulty Index ◽  
Extended Reach Drilling

Abstract Well X is an infill horizontal well designed for the Gulf of Thailand. It is challenging due to the following factors - A long 8 ½ inch open hole section, An extended reach section at horizontal or near horizontal, the presence of loss circulation zones, an Extended Reach Drilling (ERD) ratio of 2.725 and a Drilling Difficulty Index (DDI) of 6.762. The key challenge was to successfully deploy the 7 inch casing across 12,350 ftMD of open hole, with potential loss circulation zones. In spite of these difficulties, the 7 inch casing was successfully landed with the use of an Ultra-High Speed Rotational Reamer Shoe. Historically, losses of circulation have posed significant challenges to well delivery in the Gulf of Thailand wells. In Well X, this is further complicated by a long open-hole section with a step-out of over 10,000 ftMD. It was determined that the successful deployment of the 7 inch casing would require some degree of agitation at the nose, and such a device must be tolerant to the Lost Circulation Materials (LCM) type and the composition of the drilling fluid and the cement. An ultra-high speed rotational reamer shoe was specially configured to meet the LCM requirements in the displaced fluid, for use in deploying the casing. While deploying the 7 inch casing, losses of up to 20 bbls/hr occurred from 7,043 ftMD while running at 15 joints/hr. A loss circulation recipe comprising of 60 bbls of 30 ppb Tiger LCM was mixed and successfully displaced through the customized ultra-high speed reamer shoe to cure losses. The casing was washed down from 10,569 to 11,610 ftMD, filling casing each stand. The 7 inch casing was successfully landed at the target depth of 12,353 feet and subsequently cemented. Drill out operations took 1.5 hours to complete. A formation integrity test (FIT) showed good shoe strength which was later confirmed by the cement evaluation logs. The comprehensive Ultra-High Speed Reamer Shoe was configured with a minimum restriction of 15mm, which is 5 times the diameter of the maximum particle size in the LCM of 3 mm. The tool was designed to tolerate the prescribed loss circulation materials, making it possible to cure the losses while running the casing string. The innovative Ultra-High Speed Reamer Shoe has demonstrated its usefulness by providing a higher probability for successfully deploying the 7 inch production casing over the extended reach section of Well X. The application of this technology can mitigate against non-productive time such as wiper trips or excessive washing down or casing rotation. It has proven to be a reliable technology that can be used in the industry in challenging well designs.

Horizontal Well Penetration Rate Increasing Technology in Sulige Gas Field

2015 ◽  
Vol 733 ◽  
pp. 17-22
Author(s):  
Yang Liu ◽  
Zhuo Pu He ◽  
Qi Ma ◽  
Yu Hang Yu
Keyword(s):  
Horizontal Well ◽  
Economies Of Scale ◽  
Reference Value ◽  
Drilling Speed ◽  
Underground Engineering ◽  
Gas Field ◽  
Horizontal Section ◽  
Well Drilling ◽  
Drilling Parameters ◽  
Key Techniques

In order to improve the drilling speed, lower the costs of development and solve the challenge of economies of scale development in sulige gas field, the key techniques research on long horizontal section of horizontal well drilling speed are carried out. Through analyzing the well drilling and geological data in study area, and supplemented by the feedback of measured bottom hole parameters provided by underground engineering parameters measuring instrument, the key factors restricting the drilling speed are found out and finally developed a series of optimum fast drilling technologies of horizontal wells, including exploitation geology engineering technique, strengthen the control of wellbore trajectory, optimize the design of the drill bit and BHA and intensify the drilling parameters. These technologies have a high reference value to improve the ROP of horizontal well in sulige gas field.

scholarly journals Study on Thermo-Hydro-Mechanical Coupling and the Stability of a Geothermal Wellbore Structure

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 649
Author(s):  
Xiaolin Huan ◽  
Gao Xu ◽  
Yi Zhang ◽  
Feng Sun ◽  
Shifeng Xue
Keyword(s):  
Effective Stress ◽  
Cold Water ◽  
Drilling Fluid ◽  
Water Injection ◽  
Coupled Model ◽  
In Situ Stress ◽  
Excess Pore Pressure ◽  
Mechanical Coupling ◽  
Open Hole ◽  
Cement Sheath

For processes such as water injection in deep geothermal production, heat transfer and fluid flow are coupled and affect one another, which leads to numerous challenges in wellbore structure safety. Due to complicated wellbore structures, consisting of casing, cement sheaths, and formations under high temperature, pressure, and in situ stress, the effects of thermo-hydro-mechanical (THM) coupling are crucial for the instability control of geothermal wellbores. A THM-coupled model was developed to describe the thermal, fluid, and mechanical behavior of the casing, cement sheath, and geological environment around the geothermal wellbore. The results show that a significant disturbance of effective stress occurred mainly due to the excess pore pressure and temperature changes during cold water injection. The effective stress gradually propagated to the far-field and disrupted the integrity of the wellbore structure. A serious thermal stress concentration occurred at the junction of the cased-hole and open-hole section. When the temperature difference between the injected water and the formation was up to 160 °C, the maximum hoop tensile stress in the granite formation reached up to 43.7 MPa, as high as twice the tensile strength, which may increase the risk of collapse or rupture of the wellbore structure. The tensile radial stress, with a maximum of 31.9 MPa concentrated at the interface between the casing and cement sheath, can cause the debonding of the cementing sheath. This study provides a reference for both the prediction of THM responses and the design of drilling fluid density in geothermal development.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure

scholarly journals Application of Artificial Intelligence Techniques in Predicting the Lost Circulation Zones Using Drilling Sensors

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Abdulmalek Ahmed ◽  
Salaheldin Elkatatny ◽  
Abdulwahab Ali ◽  
Mahmoud Abughaban ◽  
Abdulazeez Abdulraheem
Keyword(s):  
Artificial Intelligence ◽  
Real Time ◽  
Drilling Fluid ◽  
Confusion Matrix ◽  
High Accuracy ◽  
Functional Networks ◽  
Lost Circulation ◽  
Drilling Parameters ◽  
High Pressure High Temperature ◽  
Drilling Cost

Drilling a high-pressure, high-temperature (HPHT) well involves many difficulties and challenges. One of the greatest difficulties is the loss of circulation. Almost 40% of the drilling cost is attributed to the drilling fluid, so the loss of the fluid considerably increases the total drilling cost. There are several approaches to avoid loss of return; one of these approaches is preventing the occurrence of the losses by identifying the lost circulation zones. Most of these approaches are difficult to apply due to some constraints in the field. The purpose of this work is to apply three artificial intelligence (AI) techniques, namely, functional networks (FN), artificial neural networks (ANN), and fuzzy logic (FL), to identify the lost circulation zones. Real-time surface drilling parameters of three wells were obtained using real-time drilling sensors. Well A was utilized for training and testing the three developed AI models, whereas Well B and Well C were utilized to validate them. High accuracy was achieved by the three AI models based on the root mean square error (RMSE), confusion matrix, and correlation coefficient (R). All the AI models identified the lost circulation zones in Well A with high accuracy where the R is more than 0.98 and RMSE is less than 0.09. ANN is the most accurate model with R=0.99 and RMSE=0.05. An ANN was able to predict the lost circulation zones in the unseen Well B and Well C with R=0.946 and RMSE=0.165 and R=0.952 and RMSE=0.155, respectively.

Pushing the Limits in Offshore Mexico

2021 ◽  
Author(s):  
Hector Hugo Vizcarra Marin ◽  
Alex Ngan ◽  
Roberto Pineda ◽  
Juan Carlos Gomez ◽  
Jose Antonio Becerra
Keyword(s):  
Gulf Of Mexico ◽  
Real Time ◽  
Lessons Learned ◽  
Clear Understanding ◽  
Directional Drilling ◽  
Case Histories ◽  
Control Plan ◽  
Drilling Performance ◽  
Drilling Parameters ◽  
Drilling Engineering

Abstract Given the increased demands on the production of hydrocarbons and cost-effectiveness for the Operator's development wells, the industry is challenged to continually explore new technology and methodology to improve drilling performance and operational efficiency. In this paper, two recent case histories showcase the technology, drilling engineering, and real-time optimization that resulted in record drilling times. The wells are located on shallow water in the Gulf of Mexico, with numerous drilling challenges, which typically resulted in significant Non-Productive Time (NPT). Through close collaboration with the Operator, early planning with a clear understanding of offset wells challenges, well plan that minimize drilling in the Upper Cretaceous "Brecha" Formation were formulated. The well plan was also designed to reduce the risk of stuck pipe while meeting the requirements to penetrate the geological targets laterally to increase the area of contact in the reservoir section. This project encapsulates the successful application of the latest Push-the-Bit Rotary Steerable System (RSS) with borehole enlargement technology through a proven drilling engineering process to optimize the drilling bottomhole assembly, bit selection, drilling parameters, and real-time monitoring & optimization The records drilling times in the two case histories can be replicated and further improved. A list of lessons learned and recommendations for the future wells are discussed. These include the well trajectory planning, directional drilling BHA optimization, directional control plan, drilling parameters to optimize hole cleaning, and downhole shocks & vibrations management during drilling and underreaming operation to increase the drilling performance ultimately. Also, it includes a proposed drilling blueprint to continually push the limit of incremental drilling performance through the use of RSS with hydraulics drilling reamers through the Jurassic-age formations in shallow waters, Gulf of Mexico.

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