bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactive and Weak Zone Drilling Solution: Non-retrievable Casing Drilling
Authors: Jusoh M Faizol , Wang Keith Won 
Published: July 2012

Abstract
Non-retrievable casing drilling technology has gained wide recognition from operators for drilling top hole sections in offshore Peninsular Malaysia waters in recent years. The high value realized in reduction of well construction costs and problem resolution in reactive formations has contributed to the high popularity of this innovative drilling technique in this region.
Reactive shale zones are the trouble zones commonly seen in the top hole section offshore Peninsular Malaysia. These zones are mainly comprised of soft sandstone and claystone which have caused losses of millions of dollars to operators using conventional drilling techniques. Extra wiper trips are frequently necessary across these trouble zones, and stuck casing can still be a problem.
A non-retrievable casing drilling bit, the Defyer, has been successful in avoiding lost time in penetrating these trouble zones, and previously set a casing drilling record of a 13-3/8" application in this area. This success for footage drilled achieved by the casing drilling bit provided encouragement for an attempt that would push the ultimate capability of this system in drilling a long interval through the reactive zones.
This paper briefly discusses the planning, implementation process of this long interval 13-3/8" casing drilling through reactive zone and subsequent savings for the operator in this project.
Drilling Performance Optimization on Malaysia's First Coiled Tubing Drilling Pilot Project: A Case Study
Authors: Abdul Rahman A. A. , Hamzah N. E. , Fauzi N. Ahmad , El-Hariry H. , Jenie J. R. , Chaari Y. 
Published: July 2012

Abstract
This paper presents a general discussion of the phases necessary to undertake coiled tubing drilling (CTD) project in a new area: conceptual design during the feasibility study, equipment planning and preparation, detailed engineering, and operational challenges during execution. The actual operations and performance results for these phases are given for the first CTD pilot project undertaken in Malaysia.
CTD can provide significant economic benefits when applied in the proper field setting. In addition to potential cost advantages, it can provide other benefits: safer and more efficient pressure control, faster tripping time, smaller footprint and weight, faster rig-up and rig-down, reduced environment impact, operations with fewer personnel, and high-speed telemetry. In the Malaysia project, where it was applied to the drilling of directional through-tubing reentry wells requiring casing exit methods and high dogleg capability, it provided the flexibility to access compartmentalized bypassed pockets in the reservoir. Drilling for the CTD project was started in February 2011 and completed in August 2011; three out of four wells were drilled and completed in the target formation. The challenges faced during the beginning of the execution phase were used as lessons learned and contributed to a fast learning curve, leading to delivery of the last three wells within budget.
The drilling campaign demonstrated the ability of CTD to reach small, bypassed pockets that are difficult to produce economically with conventional reentry drilling techniques. This success has opened the door for CTD of other numerous idle wells [in same field or just in Malaysia in general?], which can result in efficient recovery of the bypassed oil. This is especially important for the offshore environment of Malaysia because platforms require a significant investment that is usually not justified for such marginal reserves.
Exploration and Practice of Volume Fracturing in Shale Gas Reservoir of Sichuan Basin, China
Authors: Mingzhong Chen , Bin Qian , Zhilin Ou , Juncheng Zhang , Hai Jiang , Rui Chen 
Published: July 2012

Abstract
The commercial development of natural gas in shale formations has been realized in U.S. The exploration and production of gas in shale is closely related to the progress of fracturing technology, and fracturing stimulation is becoming the key technology for developing gas production in shale. The shale development history in the U.S shows that horizontal well technology has increased shale exploration greatly. Now horizontal wells account for 94% of production, and the production is 2–4 times that of vertical wells in developing the Barnett shale in the U.S. The newly developed volume fracturing technology, especially volume fracturing in horizontal wells improves the stimulation results of horizontal wells and is becoming the main method of increasing production in shale.
Compared with the shales in the North America, the shales in China exhibit a great difference in reservoir characteristics. The preliminary shale gas resource assessment in China shows that not only are the reserves in shale huge, but also the distribution is wide. There are two primary shale depositional environments in China, marine deposits and lacustrine deposits. The marine deposit shales are located in the south, north and northwest of China, with lacustrine deposit shales located in the northeast, north and northwest. From 2010, the exploration of shales in Weiyuan, Changning, Fushun and Zhaotong areas of the Sichuan basin started, with fracturing jobs in 7 vertical wells and 4 horizontal wells showing good results, which demonstrates the potential of shale gas exploration in China.
This paper describes the exploration and practice of volume fracturing and supporting technology in shale gas reservoirs in the Sichuan basin. The fracturing results show that some obvious complex fracture network is formed in most wells. The practice of volume fracturing in shale in Sichuan Basin shows that parameter optimization, wellsite control and application of supporting technology based on reservoir character and job objective are the keys to volume fracturing. This paper presents the summary of development of volume fracturing of shale in China and discusses the next step considerations on the basis of the shale reservoir characteristics in Sichuan Basin.
Probe on Anti-sloughing Film-forming Drilling Fluid Technologhy to Be Used When Drilling Medium Changed to Drilling Fluid During Gas Drilling
Authors: WANG Lan , MA Guangchang , LIU Bin , WU Zhengliang , WANG Canshu , CHEN Junbin , OU Yangwei , YUAN Zhiping , WU Qi , JIN Chengping , WANG Rui , HE Hai 
Published: July 2012

Abstract
After the gas drilling completed, free water in drilling fluid will influx into the formation rapidly in large volume after the drilling fluid pumped downhole. That will cause clay mineral to swell, which leads to open hole instability. In addition, it may create thick mud cakes on the open hole wall in short period, which results in borehole problems. Tight pull during tripping operation is a typical example. Whether open hole instability or the presence of thick mud cakes, it needs more time to solve problems for unrestricted borehole. Therefore, a new concept - anti-sloughing film-forming drilling fluid technology was raised in order to control open hole instability when the drilling fluid pumped downhole after the gas drilling. Essence of the technology is to film a dense waterproof diaphragm on the open hole wall to effectively prevent free water in the drilling fluid from influxing into the formation, which can avoid hydration swelling and eliminate the formation of thick mud cakes.
This technology is just under laboratory test. So far there is no on-site application.
Experimental tests show that a total fluid composed of macromolecular organics and inorganics (called film forming agent in this article) can quickly form a smooth and strong waterproof diaphragm on the surface of laboratory core within 10 secends to 30 secends. The mentioned diaphragm effectively prevents free water in the drilling fluid from influxing into the core internal. According to the laboratory appearance and results, it can be boldly deduced that if flim forming agent is used in the well after gas drilling, the waterproof diaphragm can effectively prevent free water in the drilling fluid from influxing into the formation once formed, which realizes open hole stabilization.
At present, many wells need 3 days to 4 days or more time to deal with restricted borehole problems cuased by open hole instability or thick mud cakes when drilling medium changed to drilling fuild during gas drilling. It has affected the overall effect of the gas drilling to some extent. Research on the anti-sloughing film-forming technology can help to solve such problem and recover to mud drilling normally in short period, which benefits to improve drilling efficiency and save drilling cost.
The Application of Polymer-sulfonated Saturated Salt Based Mud System on the Right Bank of the Amu Darya in Turkmenistan
Authors: Jin Chengping , Ma Guangchang , Wang Canshu , Ou Yangwei , Li Wei , He Hai , Wang Lan , Wang Xianbin 
Published: July 2012

Abstract
Due to the long section (between 700 and 1200 meters) of the anhydrite and salt in the upper Jurassic formation on the right bank of the Amu Darya in Turkmenistan, a polymer-sulfonated saturated salt (NaCl) based mud (PSSSM) system was prepared by using laboratory tests to prevent drilling fluid contamination from anhydrite and salt solids. Corresponding technical measures were determined after the laboratory testing and field application. This kind of mud system can effectively prevent down hole problems which will commonly occur in long sections of anhydrite and salt, such as plastic flow of salt and anhydrite, drilling fluids heavy contaminated by the salt and anhydrite, hole washout, pipe sticking, etc.
The PSSSM mud system can safely and effectively overcome the problems associated with these troublesome formations. More than 50 wells were drilled 100% successfully compared with other kind mud systems used in Turkmenistan. The drilling success ratio was only 40% before using this kind of mud system in this locality. A significant amount of experience was gained during the past 3 years which contributed to successful application of this fluid system.
Additionally, a lot of plant derivatives were used as fluids additives in the saturated salt water based mud system, which will satisfy the increasing of environmental concerns. All the plant derivative additives can easily be allowed to biodegrade after the completion of fluids services. Fluids recycling measures were also implemented to lower the cost and environmental impact. Sufficient mud weight (MW), amount of calcium and chloride ion needs to be maintained before and during drilling the anhydrite and salt section.
All the technical measures and conclusions have been retained for reference on future drilling in geologically similar areas. Considerations for improving the environmental impact and better reservoir protection can be made on the basis of these experiences.
Top Drive Casing Running: Improving Safety and Efficiency of the Operation
Authors: Zhang Hongying , He Tao , Wang Na , Liu Guanghua , Zou Lianyang , Huang Yanfu 
Published: July 2012

Abstract
Casing running operation is a crucial step in drilling a wellbore. With more and more horizontal wells and extended-reach wells are drilled, there is an increasing demand for a technology, which will be able to circulate the drilling fluid and rotate the casing while lowering it simultaneously to avoid pipe stuck occurs. This paper introduces the Top Drive Casing Running (TDCR) technology, which will greatly meet the challenges that are associated with casing running operations in the drilling activity.
In a seven (7) inch casing running operation of a horizontal gas well in southwest of China-Sichuan Basin, which is notorious for its complicated geological formation, the TDCR successfully set the casing to the target depth. The TDCR provided the ability to rotate, reciprocate and circulate when difficult hole conditions were encountered in the long horizontal section. The TDCR technology employed were considered as the key in the operation.
The TDCR technology extends the benefits of a top drive such as accurate torque control of makeup connections, which is especially important when making up premium connections. The ability to circulate while running casing through trouble zones will ensure wellbore integrity and avoid complicated downhole accident. Since no stabbing board operation is required, non-productive time is reduced, safety and efficiency are improved.
The TDCR technology has the potential to become a major player in casing running operation and will gain wider application in the future.
Successful Implementation of HT Geothermal Drilling Technology in Kenya
Authors: Zhang ZhaoFeng , Njee James M. , Han Min , Shan ZhengMing , Zhan Min , Sun FaSheng 
Published: July 2012

Abstract
The geothermal resources of Kenyan are located in East African Great Rift Valley. The sub surface formation has high matrix compressive strength, rapidly changing and complex lithology, abrasive, fractured and high temperatures about 350 degrees Celcius. As a result, there are many challenges encountered in drilling operations including total loss of circulation, low penetration rate, high temperature damage of directional drilling steering tools and mud motors, breakdown of drilling foam structure at high temperatures, high drill string torque, loss of cement slurry and others. By integrating conventional oil and gas drilling technology, implementation of air and foam drilling technology it has been possible to solve the loss of circulation problems, improve on hole cleaning and cuttings recovery and consequently improved the penetration rates. The application of directional drilling technology has produced wells that reach a greater portion of the reservoir by intersecting more fractures increasing geothermal wells productivity. Through proper bit selection, improved hole cleaning efficiency, reduced drill string torque, the penetration rate has been improved and also reduced the total days per well.
A total of fifty seven (57) geothermal wells have successfully been drilled between May 2007 and April 2012. The drilling operation has been 100% successful with the wells being 98% productive. The production has increased from 3 - 5Mwe per single well to 16 MW due to application of directional drilling and aerated drilling technology. This is an tremendous increase of over 100%.
This integrated high temperature geothermal drilling technology can be implemented in the entire East African Great Rift Valley system to develop the vast geothermal resources for economic development.
Successful Development of Changbei Marginal Tight Gas Field: Dual Lateral Horizontal Well and Significant Drilling Performance Improvement
Authors: Gao Erhu , Desai Harshit , Wee Si-Boon , Zhao Hongkai , Wang Xiongfei , Yang Jin 
Published: July 2012

Abstract
Changbei is a marginal tight gas field located in Yulin, China. Historically similar fields had been developed with fractured vertical wells. To improve well productivity and reserve recovery, a new concept of long dual horizontal wells (2 × 2,000m legs) has been developed to recover the gas reserves more cost effectively. The initial drilling campaign had proved to be challenging due to:
Bit balling while drilling the 12¼ hole section Difficulties in landing of the 9 5/8" production casing accurately, due to drilling of coals just above top of QA reservoir and geological uncertainties Unstable carbonaceous claystone or coal across the long horizontal reservoir sections High Non-Productive Time (NPT) due to failures of downhole equipment and drillpipe High drilling costs as a result of the above stated problems
To make the field development a success, the Changbei wells team had formed a performance improvement team, which turned around the wells performance with DTL, LEAN and Performance Improvement Staircases. As a result, the wells costs and drilling times have been halved. The team has since maintained their drive for continued drilling performance improvement and made drilling operations a successful story.
This paper will discuss the key successful factors for Changbei horizontal drilling. It will first of all introduce the dual lateral horizontal well design. This will be followed by a summary of the drilling problems encountered from the initial drilling campaign. The paper will then address how the various tools such as DTL, LEAN (a step-change performance improvement methodology) process, RTOC and Performance Improvement Plan (PIP) have been applied effectively to drive down the drilling times and wells costs, with the application of selected localized products and services.
It will also illustrate how to manage changes during horizontal wells drilling campaign with two case studies including change of the drilling strategy and the re-drill of one of the horizontal legs in well CB8-3.
Coiled Tubing Working Life Prediction Based on BP Algorithm of Artificial Neural Network
Authors: Peng Song , Xiao Jian-qiu , Tian Yi , Zhang Ye , Feng Jie , Hu Zhi-jian 
Published: July 2012

Abstract
The fatigue under bending and internal press is the main reason for coiled tubing (CT) failure. Because the conventional life prediction methods for estimating coiled tubing working life under multi-axial loading are not ideal, a new method was proposed to predict the coiled tubing working life by using its nonlinear approximation and generalization abilities based on the back propagation (BP) artificial neural network (ANN). The CT diameter, wall thickness and internal pressure were used as ANN training input vectors, while the experimental cycle times of the CT was used as training target vectors. A three-layer BP neutral network was built and trained by training samples. And the ANN model was verified by training samples and testing samples. The results showed that predicted values was comparatively consistent well with experimental data, moreover, the precision of this method was superior to that applied by the conventional life prediction model. The feasibility of predicting the coiled tubing working life by applying the BP ANN was proved. The above method provides a new route for developing the coiled tubing working life tracking and monitoring software and improving the application level of the coiled tubing for the field use.
Wavelet Packet Noise Reduction Algorithm Based Near-bit Resistivity Measurement Method and Device
Authors: Jia Hengtain , Sheng Limin , Dou Xiurong , Deng Le , Guan Kang , Fan Jinhui 
Published: July 2012

Abstract
Rock resistivity has a close relationship with lithology, reservoir properties and oil-bearing capacity. Resistivity measurement while drilling (MWD) device is designed to judge Lithology, divide oil/gas/water layer and analyze the oil-bearing capacity, permeability and porosity of reservoir according to measurements of rock resistivity. It is used for real-time evaluation of stratum. The porous stratum is commonly high in resistivity. Low resistivity measured often implies the existence of saturation water. However, the collected information that reflects the resistivity signal contains a lot of noise components. It is difficult to accurately reflect the formation resistivity. The near-bit RMWD device based on wavelet packet noise reduction algorithm can measure the resistivity of stratum at first time because of the method of measurement while drilling. It can also precisely denoise the measured data of lateral resistivity, bit resistivity and azimuthal resistivity by the algorithm of wavelet packet decomposition and the best wavelet tree of reconstruction signal based on information entropy, so as to improve the accuracy and reliability of resistivity measurement.
Design and Application of 735hp 4000m Plateau Mountain Rig
Authors: Yan Zengxuan , Xu Hongwei , Liu Guanghui , Li Qinghong , Wang Jianhong , Ma Xianping , Zhao Feng , Li Qingyu , Yang Shiquan , Sun Lin 
Published: July 2012

Abstract
Installation occupies a small area, the 735hp (4,000m) plateau mountain rig can meet the requirement of drilling operation in plateau mountain area with complex topographic conditions and is characterized by low operation cost, low oil consumption and good economical efficiency.
Application of Aluminum & Amino Drilling Fluid in Drilling Encountering Massive Coal
Authors: Xiong Kaijun , Ma Pingping , Yong Fuhua , Qian Feng , Yang Rongkui , Meng Youpeng 
Published: July 2012

Abstract
In Block Baka of Tuha Oilfield, China, because of coalseam, the borehole is unstable extremely, complex problems, accidents occured in downhole frequently, prolonged drilling period and reduced drilling rate. For the sake of safe operation with drilling in coalseam encountered, this study analyzed the primary reasons that weak anti-collapse ability and poor inhibitive ability resulted in complexities. Strong inhibitor and anti-caving agent were optimized by experiments. Finally, Aluminum & Amino Drilling Fluid formulation was developed. Aluminum & Amino Drilling Fluid provides many advantages with better rheological performance, less fluid lose and high temperature resistance, in particular, it has strong inhibitive ability and anticollapse ability.
Aluminum & Amino Drilling Fluid was applied from 2000–3527m in well Ke 21-Ping 1 while drilling. 64 layers of coalseam with 136m in total and 30 layers of carbonaceous shale with 49m in total were drilled. The thickness of single coalseam is up to 34m; 2 layers of coalseam with 11m and 58m thickness were encountered in directional interval in well Ke 33-Ping, and no borehole problems and accidents happened. Good results were obtained from the application of the drilling fluid in two wells on site.
In order to drill massive coalseam safely, and to improve the anti-collapse and inhibitors, the drilling fluid was applied to two wells in Block Baka successfully. The strong inhibitor and the efficient anti-caving agent played a positive role in stabilizing borehole in thick coal layers, and reduced complex circumstances effectively.
Therefore, Aluminum & Amino Drilling Fluid can ensure the stability of sidewall in the formation with thick coalseam, and reduce the complexities effectively; it played an important role in improving drilling rate and drilling efficiency, and accumulated a valuable experience for safety drilling in deep and complex formation.