Optimizing Bottom Hole Assembly Design Criteria to Improve Mechanical Performance in Slim Hole Drilling Environment

2021 ◽  
Author(s):  
Stephen Fleming ◽  
Roberto Ucero ◽  
Yuliya Poltavchenko
Keyword(s):  
Mechanical Performance ◽  
State Of The Art ◽  
Hole Drilling ◽  
Force Analysis ◽  
Software Suite ◽  
Assembly Design ◽  
Positive Displacement ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Bottom Hole Assembly

Abstract After analyzing the historical data of neighboring wells adjacent to the drilling site, 11 bit trips were required due to the low mechanical performance of the bottom hole assembly elements. This observation is based on maximum circulation hours and low helical bucking values that make it uneconomic to drill the sections with a positive displacement motor drive system. A redesign the bottom hole assembly was proposed to achieve an improved mechanical performance which allowed the section to be drilled with a single assembly. With a focus on increasing the mechanical limitations of the downhole elements, the use of 4 ¾" equipment is considered instead of the 3 ½" standard equipment used in this hole size. One of the biggest challenges was modifying the 4 ¾" positive displacement motor (PDM) to fit into the 5 ½" hole given that the mud motor has a maximum unmodified diameter of 5 ½". Using the force analysis module of a State-of-the-art BHA modelling software suite, multiple iterations were performed to simulate and validate an alternative PDM design and accompanying directional assembly. This new design featured modifications to an existing 4 ¾" PDM deploying a long gauge bit in combination with a fit for purpose measurement while drilling system. After numerous runs using this assembly design, it was found that there was no additional or unexpected wear of the modified Mud Motor components or associated elements of the downhole equipment. These observations act to validate the pre-job engineering force analysis. With the improved mechanical specifications of the 4 ¾" Bottom Hole Assembly (BHA) components, circulating hours were increased from 100 hours to 250+ hours in a stepwise process. This enabled drilling of the entire 5 ½" section with a single BHA, comparing favorably to the legacy approach with an average of eleven bit runs. The modified 4 ¾" PDM coupled with long gauge bit technology enabled a reduction in the oriented to rotate drilling ratio and an associated increase in the overall rate of penetration (ROP). It can be concluded that the substitution of 4 ¾" drilling equipment for 3 ½" in the 5 ½" hole section, increased the drilling efficiency between 30-50% according to field data obtained in Ukraine. The modified 4 ¾" PDM combined with long gauge bit technology has the potential to improve 5 ½" hole drilling performance in other locations. Following a structured planning process using State-of-the-art BHA modelling software suite enabling the evaluation of the significant forces that act in the drilling assembly and so significantly reducing the risks associated with exceeding the original design limits of the assembly. By improving the mechanical performance of the drilling assembly in a 5 ½" hole, new territory for drilling engineers and design engineers is now available to increase the drilling performance in slim wellbores.

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

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.

Application Of Tandem Rotary Steerable-Positive Displacement Motor Bottom Hole Assembly In Drilling Horizontal Wells: Case Study Of Three East Siberia Wells

2011 ◽  
Author(s):  
Zimuzor Michael Okafor ◽  
Andrew John Buchan ◽  
Dmitry Diyanov ◽  
Sheldon Andre Rawlins ◽  
Grigoriy Zhadan ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
East Siberia ◽  
Positive Displacement ◽  
Bottom Hole ◽  
Bottom Hole Assembly

HORIZONTAL DRILLING IN AUSTRALIA: THREE CASE HISTORIES

1991 ◽  
Vol 31 (1) ◽  
pp. 354
Author(s):  
Russell McNicoll
Keyword(s):  
Oil And Gas ◽  
Design Parameters ◽  
Horizontal Drilling ◽  
Assembly Design ◽  
Oil And Gas Fields ◽  
Bottom Hole ◽  
Directional Control ◽  
Bottom Hole Assembly ◽  
Gas Fields ◽  
Drilling Time

Three horizontal wells with horizontal sections of up to 331 m were drilled successfully during the development of the marginal North Herald and South Pepper oil and gas fields, which have relatively thin oil columns (6 to 12 m) at a depth of some 1200 m sub-sea. A steerable motor system was used to maintain directional control within the design parameters. This system proved to be successful from the start and no major changes to the bottom hole assembly design were required to drill all the wells. Average drilling time including running and setting the seven inch liner amounted to 12 days. The wells were tested with rates up to 7500 BOPD through a one inch choke.

Calculation Methods of Orienter Torque and Drag in Coiled Tubing Drilling

2014 ◽  
Vol 1065-1069 ◽  
pp. 2049-2052
Author(s):  
Liang Hu ◽  
De Li Gao
Keyword(s):  
Static Friction ◽  
Maximum Output ◽  
Force Analysis ◽  
Viscous Forces ◽  
Coiled Tubing ◽  
Bottom Hole ◽  
Weight On Bit ◽  
Bottom Hole Assembly ◽  
The Impact ◽  
The Relationship

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.

Model Development of Torsional Drillstring and Investigating Parametrically the Stick-Slips Influencing Factors

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Parimal Arjun Patil ◽  
Catalin Teodoriu
Keyword(s):  
Nonlinear Differential Equations ◽  
Torsional Oscillation ◽  
Stick Slip ◽  
Friction Forces ◽  
Rock Interaction ◽  
Torsional Oscillations ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Drilling Parameters ◽  
Bottom Hole Assembly

Drillstring vibration is one of the limiting factors maximizing drilling performance. Torsional vibrations/oscillations while drilling is one of the sever types of drillstring vibration which deteriorates the overall drilling performance, causing damaged bit, failure of bottom-hole assembly, overtorqued tool joints, torsional fatigue of drillstring, etc. It has been identified that the wellbore-drillstring interaction and well face-drill bit interaction are the sources of excitation of torsional oscillations. Predrilling analysis and real time analysis of drillstring dynamics is becoming a necessity for drilling oil/gas or geothermal wells in order to optimize surface drilling parameters and to reduce vibration related problems. It is very challenging to derive the drillstring model considering all modes of vibrations together due to the complexity of the phenomenon. This paper presents the mathematical model of a torsional drillstring based on nonlinear differential equations which are formulated considering drillpipes and bottom-hole assembly separately. The bit–rock interaction is represented by a nonlinear friction forces. Parametric study has been carried out analyzing the influence of drilling parameters such as surface rotations per minute (RPM) and weight-on-bit (WOB) on torsional oscillations. Influences of properties of drillstring like stiffness and inertia, which are most of the times either unknown or insufficiently studied during modeling, on torsional oscillation/stick-slip is also studied. The influences of different rock strength on rate of penetration (ROP) considering the drilling parameters have also been studied. The results show the same trend as observed in fields.

scholarly journals THE APPLICATION FEATURES OF DIRECTIONAL BHAS WHILE DRILLING DIRECTIONAL WELLS

2019 ◽  
pp. 17-24
Author(s):  
I.I. Chudyk ◽  
A.M. Livinskyi ◽  
Akhmed Al Tanakchi ◽  
A.M. Pastuch
Keyword(s):  
Design Feature ◽  
Axial Displacement ◽  
Energy Costs ◽  
Assembly Design ◽  
Bottom Hole ◽  
Drilling Method ◽  
Bottom Hole Assembly ◽  
Energy Consuming ◽  
Analytical Research ◽  
Physical And Mechanical Characteristics

The article presents a scientific and practical approach to assessing the energy efficiency of directional bottom hole assembly on the basis of the mud motor. The main design feature of these assemblies is the presence of a bent angle in the spindle section of the mud motor. The conditions of operation of such assemblies are considered for a combined drilling method with a various number of stabilizers. Particular attention is paid to determining the causes of unproductive energy costs on the work of the directional bottomhole assemblies in the borehole.The mathematical model improved by the authors includes the geometric features of the assembly design, the bent angle of the spindle of the mud motor as to its body, the number of the stabilizers and the location of their installation, the borehole inclination angle, the physical and mechanical characteristics of the subsurface rock that forms it. The authors calculated the energy consumption for rotation and the axial displacement of the assemblies in the directional well taking into account the deflection forces on the bit and the reaction on the stabilizers. The researchers suggest the use of the indicator of specific energy costs to overcome the forces and moments of the environment resistance during the work of the directional assemblies using the method of combined drilling.Using the results of analytical research and the developed approach the authors study energy costs for thework of the directional bottom hole assemblies with a various number of the stabilizers. The study is conducted for the slick assemblies, as well as for assemblies with one- and two-stabilizers. It is established that directional assemblies with one stabilizer are characterized by the highest values of the forces of resistance of axial displacement and rotation in the directional well. As they are high-torque, energy-consuming and the most energy-intensive systems, their practical use is limited. The main factors in the formation of energy costs for the work of directional assemblies while applying the combined drilling method are the number of the stabilizers and the inclination range.

Hybrid Drill Bit Technology on Performance Motor Bottom Hole Assembly Yields Breakthrough Drilling Performance in Kuwait

2019 ◽  
Author(s):  
Waleed Al-Baghli ◽  
Mohammad Al-Salamin ◽  
Sulaiman Sulaiman ◽  
Atef Abdelhamid ◽  
Ali Alnemer ◽  
...  
Keyword(s):  
Drill Bit ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Bottom Hole Assembly

Vibrations Increase Available Power at the Bit

1985 ◽  
Vol 107 (1) ◽  
pp. 138-141 ◽  
Author(s):  
D. W. Dareing
Keyword(s):  
Penetration Rate ◽  
Fatigue Loading ◽  
Vibration Energy ◽  
Assembly Design ◽  
Positive Side ◽  
Drilling Equipment ◽  
Bottom Hole ◽  
Dynamic Forces ◽  
Bottom Hole Assembly ◽  
Rotary Speed

Drillstring vibrations are generally considered to be detrimental to downhole drilling equipment because they produce cyclic or fatigue loading. Tool joint failures, tubular washouts, and bit breakage are often fatigue related. On the positive side, dynamic forces applied to roller cone rock bits have the potential to increase penetration rate. This paper quantifies the available vibration energy at the bit and shows how to control the level of energy through bottom hole assembly design and rotary speed.

Post Well Vibration Analysis in the North Sea: A Tool to Understand Drilling Performance

2015 ◽  
Author(s):  
M. F. Al Dushaishi ◽  
R. Nygaard ◽  
E. Hoel ◽  
S. Hellvik ◽  
M. Andersen
Keyword(s):  
North Sea ◽  
Vibration Damping ◽  
Rate Of Penetration ◽  
Drill Stem ◽  
The North ◽  
Drilling Performance ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The North Sea ◽  
The Impact

Severe drill stem vibrations could leads to excessive damage to the bottom hole assembly causing an increase in nonproductive time. Different drill stem vibrations models are used to predict and avoid resonance regions by optimizing the selection of bottom hole assembly components and operating parameters such as weight on bit, and surface RPM. In addition to avoid the resonance regions, specialized tools have been developed to reduce vibrations. However a complete understanding on how to mitigate vibration and its effect on drilling performance is still lacking. This study investigates the cause of drill stem vibrations, its effect on drilling performance, and the effect of including vibration reductions tools in the bottom hole assembly design in several recent drilled wells in the North Sea. Vibration damping tools used in this study were able to reduce both lateral and torsional drill stem vibration compared to a well with no vibration damping tool. Torsional drill stem vibrations tend to increase through rich sand zones causing an increase in lateral vibrations. The impact drill stem vibrations have on drilling performance was identified through rate of penetration. As lateral vibration intensity increases, instantaneous rate of penetration decreases.

scholarly journals Numerical Modeling of Dynamic Behavior and Steering Ability of a Bottom Hole Assembly with a Bent-Housing Positive Displacement Motor Under Rotary Drilling Conditions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2568 ◽  
Author(s):  
Yingjie Chen ◽  
Jianhong Fu ◽  
Tianshou Ma ◽  
Anping Tong ◽  
Zhaoxue Guo ◽  
...  
Keyword(s):  
Dynamic Stress ◽  
Impact Force ◽  
Axial Loading ◽  
Drill Bit ◽  
Deviation Angle ◽  
Rotary Drilling ◽  
Positive Displacement ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The Impact

Fully rotary drilling is one of many useful technologies used for the exploitation of petroleum and geothermal resources, but fully rotating drill-strings are extremely complicated. Therefore, according to the Hamilton principle, a non-linear coupled bottom hole assembly (BHA)-bit-formation-wellbore model is proposed for BHAs with bent-housing positive displacement motor using the finite element method to investigate the dynamic behavior and steering ability under fully rotary drilling. The impact force, acceleration, axial loading, torque, and dynamic stress were simulated, and factors influencing the dynamic steering forces were investigated. The results indicate that the impact force, acceleration, axial loading, torque, and dynamic stress under fully rotary drilling are much higher than under conventional drilling. The numerical simulation and field test in well B confirmed that the rotation of the drill-string is conducive to the hold-on of the deviation angle. With the increase in the weight-on-bit, bend angle, and stabilizer height, the deflecting force on a drill bit increases. Conversely, with the increase in stabilizer diameter, the deflecting force on the drill bit decreases; the lower the deflecting force, the better the effectiveness of hold-on. With increasing deviation angle, the deflecting force on the drill bit first decreases and then increases. The present model can provide a theoretical basis for wellbore trajectory control and optimization design of BHA.

Sign in / Sign up

Export Citation Format

Share Document