Extended-Reach Drilling—Offshore California: An Operator's Experience With Drilling a Record Extended-Reach Well

2008 ◽  
Author(s):  
Michael W. Walker
Author(s):  
Hao Zeng ◽  
Yijin Zeng ◽  
Feifei Zhang ◽  
Guang Yang ◽  
Yuezhi Wang ◽  
...  

Abstract Insufficient hole cleaning is one of the major challenges in drilling, particularly in extended-reach drilling (ERD). This paper presents a case study of a stuck pipe incident caused by cuttings pack off during drilling an extended-reach well. A generalized, transient, solid-transport model that can handle different flow patterns is used to replay the hole-cleaning process. Results show that, although cuttings beds in the deviated part of the wellbore are not significant while drilling ahead, cuttings can still cause problems during tripping. This study reinforces the facts that hole cleaning in wells with long deviated sections is complicated and a transient approach is required to fully understand the hole-cleaning condition. Effective hole cleaning does not only mean that the cuttings concentration is low or the cuttings transport ratio is high. In addition, the absence of additional cuttings being produced from the shale shaker during circulation does not necessarily indicate that the hole is clean. The cuttings accumulated behind the BHA can lead to tight spots and over-pull incidents during tripping. By conducting drill string reciprocations without circulation, the tight spots can be “worked through” but packed cuttings cannot be removed from the wellbore. This paper presents lessons learned from this incident, as well as recommendations for future operations.


2011 ◽  
Vol 361-363 ◽  
pp. 386-392
Author(s):  
Hui Zhang ◽  
De Li Gao ◽  
Wen Sheng Liu

Drilling is one of the major means for oil and gas exploration and development. Extended reach wells (ERWs) are defined as directional wells or horizontal wells with horizontal displacement (HD) to vertical depth (VD) ratio greater than or equal to 2. Extended reach drilling (ERD) confronted many technical difficulties. Risk analysis of ERD before drilling is of great significance for preventing complex accidents during drilling operations, improving the drilling rate and efficiency. Based on gray matter-element theory, this paper established a comprehensive risk assessment model for ERD operations and applied this model to evaluate the drilling risk of Well B6ERW07(HD to VD ratio 5.94, horizontal displacement 7,419.42 m, vertical depth 1,248.50 m, measured depth 8,144.31 m)in the Liuhua oil field, South China Sea. The assessment results show that the predicted success rate of drilling this ERW is 49.9%. This result can be important criteria and thus contributes greatly to decision making.


2011 ◽  
Vol 101-102 ◽  
pp. 339-342
Author(s):  
Lian Zhong Sun ◽  
De Li Gao

There are some problems such as down hole torque & drag, casing wear and so on in extended reach drilling. Therefore, friction reducers are used widely to keep the drillstring away from the cased hole in extended reach drilling. Currently, the optimum placement of friction reducers is dependent on the drillstring deflection. Friction reducers are often connected to drill pipes by tool joints, which limits their optimum placement. In addition, the placement of the first reducer is often determined by drilling engineers’ experience. The effect of friction reducer on torque & drag is assessed in this paper and the optimum placement of friction reducer is obtained to minimize the torque & drag.


2021 ◽  
Vol 11 (6) ◽  
pp. 2743-2761
Author(s):  
Caetano P. S. Andrade ◽  
J. Luis Saavedra ◽  
Andrzej Tunkiel ◽  
Dan Sui

AbstractDirectional drilling is a common and essential procedure of major extended reach drilling operations. With the development of directional drilling technologies, the percentage of recoverable oil production has increased. However, its challenges, like real-time bit steering, directional drilling tools selection and control, are main barriers leading to low drilling efficiency and high nonproductive time. The fact inspires this study. Our work aims to contribute to the better understanding of directional drilling, more specifically regarding rotary steerable system (RSS) technology. For instance, finding the solutions of the technological challenges involved in RSSs, such as bit steering control, bit position calculation and bit speed estimation, is the main considerations of our study. Classical definitions from fundamental physics including Newton’s third law, beam bending analysis, bit force analysis, rate of penetration (ROP) modeling are employed to estimate bit position and then conduct RSS control to steer the bit accordingly. The results are illustrated in case study with the consideration of the 2D and 3D wellbore scenarios.


1995 ◽  
Author(s):  
J.M. Benesch ◽  
G. Camacho A. ◽  
S. Matsuzawa ◽  
C.R. Dawson
Keyword(s):  

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