Analytical studies of bottom hole assembly dynamics in directional well while drilling with coiled-tubing system

Hydraulic orienter has been widely used to alter the drilling direction downhole in coiled tubing drilling. A problem is encountered in construction field. When torque and drag of bottom hole assembly (BHA) are over the maximum output torque of orienter, This caused that it difficult to orient. Therefore, we need to calculate the maximum torque and drag in the process of orientation, it can provide a theoretical basis for designing and selecting the hydraulic orienter. Compared with the conventional force analysis, this paper additionally considered the case of zero weight on bit (WOB), the impact of the mud viscous forces and the relationship between dynamic and static friction, so that we can get more precise result of force analysis.

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A New, Integrated, Wireline-Steerable, Bottom Hole Assembly Brings Rotary Drilling-Like Capabilities to Coiled Tubing Drilling

10.2118/37654-ms ◽

1997 ◽

Author(s):

D.R. Anderson ◽

Alain Dorel ◽

Roy Martin

Keyword(s):

Rotary Drilling ◽

Coiled Tubing ◽

Bottom Hole ◽

Bottom Hole Assembly

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An Experimental Study of Flow Behavior of Coiled Tubing Drilling System

Advances in Mechanical Engineering ◽

10.1155/2014/935159 ◽

2014 ◽

Vol 6 ◽

pp. 935159 ◽

Cited By ~ 1

Author(s):

Feng Guan ◽

Weiguo Ma ◽

Yiliu Tu ◽

Chuanxi Zhou ◽

Ding Feng ◽

...

Keyword(s):

Pressure Drop ◽

Partial Pressure ◽

Engineering Practice ◽

Straight Tube ◽

Curvature Ratio ◽

Pressure Losses ◽

Coiled Tubing ◽

Bottom Hole ◽

Bottom Hole Assembly ◽

Drilling System

Coiled tubing drilling has become an important development direction of drilling. The method of combining theoretical calculation with the experimental verification is adopted to analyze the flow of the coiled tubing drilling system. A set of experimental bench is developed, three kinds of curvature ratio of coiled tubing are used, and the frictional pressure losses of coiled tubing and partial pressure drop of each downhole tool are tested. The results of experiments with water agree well with rough pipe calculation model. The pressure losses of coiled tube are obviously larger than that of straight tube, and the value of it is about 11–17%. The larger the curvature ratio is, the more the pressure losses of coiled tubing are. The fluid experiment with the polymer presents obviously the drag reduction effect. Experiment of simulated bottom hole assembly shows that partial pressure drop of bottom hole assembly is large. It has a little effect on the pressure losses of coiled tubing when whole bottom hole assemblies are connected. The research results can be used as the basis for formulating coiled tubing drilling process parameters, which will provide a guide for engineering practice.

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New High Temperature Coiled Tubing Drilling Bottom Hole Assembly Enables Slimhole Re-Entry Drilling in Challenging High Temperature Wells

10.2118/199842-ms ◽

2020 ◽

Author(s):

Stefan Krueger ◽

Kai Schoenborn

Keyword(s):

High Temperature ◽

Coiled Tubing ◽

Bottom Hole ◽

Bottom Hole Assembly

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Bottom Hole Assembly Design Enhancement Successfully Eliminate Hole Problems and Reduce Significant Drilling Time : South S Field Case Study

Proc. Indon. Petrol. Assoc., Digital Technical Conference, 2020 ◽

10.29118/ipa20-e-71 ◽

2020 ◽

Author(s):

Y. D. Mulia

Keyword(s):

Contact Area ◽

Cost Savings ◽

Assembly Design ◽

Drilling Performance ◽

Bottom Hole ◽

Unconsolidated Sand ◽

Bottom Hole Assembly ◽

Drilling Parameter ◽

Drilling Time

For S-15 and S-14 wells at South S Field, drilling of the 12-1/4” hole section became the longest tangent hole section interval of both wells. There were several challenges identified where hole problems can occur. The hole problems often occur in the unconsolidated sand layers and porous limestone formation sections of the hole during tripping in/out operations. Most of the hole problems are closely related to the design of the Bottom Hole Assembly (BHA). In many instances, hole problems resulted in significant additional drilling time. As an effort to resolve this issue, a new BHA setup was then designed to enhance the BHA drilling performance and eventually eliminate hole problems while drilling. The basic idea of the enhanced BHA is to provide more annulus clearance and limber BHA. The purpose is to reduce the Equivalent Circulating Density (ECD,) less contact area with formation, and reduce packoff risk while drilling through an unconsolidated section of the rocks. Engineering simulations were conducted to ensure that the enhanced BHA were able to deliver a good drilling performance. As a results, improved drilling performance can be seen on S-14 well which applied the enhanced BHA design. The enhanced BHA was able to drill the 12-1/4” tangent hole section to total depth (TD) with certain drilling parameter. Hole problems were no longer an issue during tripping out/in operation. This improvement led to significant rig time and cost savings of intermediate hole section drilling compared to S-15 well. The new enhanced BHA design has become one of the company’s benchmarks for drilling directional wells in South S Field.

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BENDING OF COILED TUBING AT THE BOTTOM HOLE AND THE WELLHEAD

Construction of Oil and Gas Wells on Land and Sea ◽

10.30713/0130-3872-2019-6-21-23 ◽

2019 ◽

pp. 21-23

Author(s):

A.V. Matsko ◽

◽

V.T. Lukyanov ◽

V.Yu. Bliznyukov ◽

Keyword(s):

Coiled Tubing ◽

Bottom Hole

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Kinematics and dynamics analysis of new rotary-percussive PDM drilling tool

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1177/1461348421989156 ◽

2021 ◽

pp. 146134842198915

Author(s):

Jialin Tian ◽

Xuehua Hu ◽

Liming Dai ◽

Lin Yang ◽

Yi Yang ◽

...

Keyword(s):

Drill String ◽

Structure Design ◽

Drilling Process ◽

Analysis Model ◽

Drilling Tool ◽

Stick Slip ◽

Rate Of Penetration ◽

Bottom Hole ◽

Bottom Hole Assembly ◽

The Impact

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.

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Underbalanced Drilling with Coiled Tubing: A Case Study on the Alaskan North Slope, Which Proves the Benefits of Drilling a Straight Hole

10.2118/204418-ms ◽

2021 ◽

Author(s):

Antoni Miszewski ◽

Adam Miszewski ◽

Richard Stevens ◽

Matteo Gemignani

Keyword(s):

Relative Effectiveness ◽

Shallow Depth ◽

North Slope ◽

Coiled Tubing ◽

The North ◽

North Slope Of Alaska ◽

Minimum Requirements ◽

Bottom Hole Assembly ◽

Alaskan North Slope ◽

Future Work

Abstract A set of 5 wells were to be drilled with directional Coiled Tubing Drilling (CTD) on the North Slope of Alaska. The particular challenges of these wells were the fact that the desired laterals were targeted to be at least 6000ft long, at a shallow depth. Almost twice the length of laterals that are regularly drilled at deeper depths. The shallow depth meant that 2 of the 5 wells involved a casing exit through 3 casings which had never been attempted before. After drilling, the wells were completed with a slotted liner, run on coiled tubing. This required a very smooth and straight wellbore so that the liner could be run as far as the lateral had been drilled. Various methods were considered to increase lateral reach, including, running an extended reach tool, using friction reducer, increasing the coiled tubing size and using a drilling Bottom Hole Assembly (BHA) that could drill a very straight well path. All of these options were modelled with tubing forces software, and their relative effectiveness was evaluated. The drilling field results easily exceeded the minimum requirements for success. This project demonstrated record breaking lateral lengths, a record length of liner run on coiled tubing in a single run, and a triple casing exit. The data gained from this project can be used to fine-tune the modelling for future work of a similar nature.

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The Study of the Interaction of Different Arrangements of the Bottom-Hole Assembly with the Bottomhole and the Borehole Wall

Prospecting and Development of Oil and Gas Fields ◽

10.31471/1993-9973-2019-3(72)-58-68 ◽

2019 ◽

pp. 58-68

Author(s):

Ya. M. Kochkodan ◽

A.I. Vasko

Keyword(s):

Differential Equations ◽

Contact Point ◽

Point Contact ◽

Drill String ◽

Borehole Wall ◽

Deviation Angle ◽

Technological Parameters ◽

Bottom Hole ◽

Anisotropy Index ◽

Bottom Hole Assembly

The article presents the main factors affecting the buckling when drilling vertical wells. The authors study analytically the effect of the weight on the bit and the force of the interaction of a drill string with a borehole wall using a uniform-sized arrangement of the bottom-hole assembly and the borehole wall which is located in a deviated wellbore when drilling in isotropic rocks in case the drilling direction coincides with the direction of the force acting on the bit. Differential equations of the elastic axis of the drill string are worked out. The solutions of these equations have given nondimensional dependences between the technological parameters. The authors have obtained the graphical dependences of the distance from the bit to the “drill string - borehole wall” contact point and the normal reaction of the bottom to the bit and the “drill string - borehole wall” clearance. The dependence for identifying the drilling anisotropy index in oblique beds is obtained. An interrelation between the anisotropy drilling index, the zenith angle, the bedding angle, the bottom-hole assembly, the borehole dimensions and the axial weight on the bit has been established. The authors have studied analytically the effect of the weight on the bit and the force of the “drill string - borehole wall” interaction, when installing the centralizer to the bottom-hole assembly. The differential equations of the elastic axis of the drill string with the centralizer in the bottom-hole assembly are obtained. It is established that with the increase in the axial weight on the bit and the “drill collars - borehole wall” clearance, the distance from the bit to the contact point of the borehole wall decreases; whereas with the increase of the deviation angle and the clearance, the pressure force of the column on the walls increases. It has also been established that the anisotropy drilling index reduces the distance from the bit to the point contact both in a slick BHA and in the bottom hole assembly with the centralizer. The presence of a centralizer in the bottom hole assembly increases the distance from the bit to the contact point between the string and the borehole wall, makes it possible to increase the weight on the bit without the risk of increasing a deviation angle.

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