bluuebunny/crossref_metadata_2025_split huggingface dataset:
Logging While Drilling LWD Formation Pressure Testing Technology Enables Better Reservoir Understanding and Completion Optimisation
Authors: Tran Pei-Chea , Jones Glyn , Bokides Nick 
Published: August 2016

Abstract
Esso Australia Resources Pty Ltd, along with joint venture partner BHP Billiton (Bass Strait) Pty Ltd, recently undertook drilling of development wells in order to access new reservoirs in the Gippsland Basin, offshore Victoria. This development of new reservoirs required confirmation of the drive mechanisms in the different stacked reservoirs to finalise the completions for each of the wells.
To confirm the pre-drill understanding of the reservoir behavior in this particular field the logging-while-drilling formation pressure testing technology was deployed, in a total of five (5) wells, throughout the development drilling campaign. The main objectives were to confirm fluid type and connectivity across the penetrated reservoirs, comparison of the logging-while drilling (LWD) data with existing wireline datasets to confirm drive mechanism and to aid in determining fluid contacts within the penetrated reservoirs.
This paper discusses the advantages and benefits of deploying a formation tester in a LWD environment, the results that were achieved and how these objectives were met. Formation pressure while drilling technology provides many advantages for formation evaluation capabilities. In particular operators can collect formation pressure measurements in highly deviated wells whilst reducing operational risks and minimizing costs. The measurements are acquired with the same technology that is used in equivalent wireline formation testers and therefore provide the same high quality data but in a drilling environment. In addition the LWD formation tester has proprietary features to optimize achieving valid pressure measurements during each deployment which will be discussed further in this paper.
As a result of the five successful separate runs a better understanding of the drive mechanisms of the separate reservoirs was achieved which enabled adjustment and optimization of the completion design. In addition, the formation pressure data was used to determine fluid contacts within reservoirs and aid in resolving LWD petrophysical log ambiguity.
Mathematical Model Provides Annular Temperature Profile for Thermal Hydraulics in Drilling Gas Hydrates
Authors: Guo Boyun , Li Gao , Shan Liqun , Li Ben 
Published: August 2016

Abstract
Production of natural gas from unconventional gas-hydrate reservoirs faces several challenges. One of them is the well control issue due to the natural gas released from gas hydrates during well drilling. It is very important for drilling engineers to know if the temperature of drilling fluid in the borehole is lower than the critical temperature that causes hydrate dissociation. However, there is no method to predict the fluid temperature with consideration of the effects of Joule-Thomson cooling and drilling cuttings entrained at the bottom hole. This paper fills the gap. An analytical model was developed in this study for predicting temperature profile in drilling gas-hydrate deposits. Result from the analytical model was verified by a numerical model developed using finite difference method. A case study indicates a good consistency between model-implications and field observations. Sensitivity analyses with the model show that the bottom-hole temperature in gas-hydrate drilling is dominated by the temperature and flow rate of the injected drilling fluid. The temperature of drilling fluid in the annulus can become greater than the geo-temperature at the same depth at high fluid flow rate. The Joule-Thomson cooling effect below the drill bit nozzles rapidly diminishes in a short interval above the bottom hole due to the heating effect of geo-thermal gradient. The rate of penetration of drill bit has negligible effect on the fluid temperature profile due to the low percentage of heat flow contributed by the entrained drill cuttings. This paper provides drilling engineers a rigorous method for predicting wellbore temperature profile during drilling gas-hydrates reservoirs.
Damage of Fracture Face Skin in Massive Hydraulic Fracture Stimulation
Authors: Shuai Li , Bo Cai , Yunhong Ding , Yongjun Lu , Chunming He 
Published: August 2016

Abstract
Multi-stage fractured horizontal wells can create fracture networks and increase the contact area between fracture and matrix to enhance well productivity and EOR. It has become a tendency to pump large volumes of fluids and proppants with higher and higher slurry rate during hydraulic stimulation. While field production has presented that not all productivities have positively relation with the increase of stimulation scales. Some small-scale fractured wells even perform better than the massive treatment ones.
To investigate this phenomenon, a new evaluation experiment studied by CT scanning and rock mechanics testified the existence of the fracture surface damage, and some key factors were revealed. Moreover, we established a new mathematical model of fracture surface skin with segment characteristics using fluid coupling method based on the classical model of PKN and KGD. Comparison of the Cinco-Ley model and new model revealed that influence of the fracture surface damage skin on productivity was only 5% using Cinco-Ley model, while the influence was 50% using our new model.
The results indicated that for a specific low permeability reservoir, if high net pressure can't create complex fracture, it would bring formation damage in the near well. We put forward a method for low damage treatment as following: 1)utilize the newly developed fracturing fluids such as slick water, low concentration densifier, linear gel (not cross linked), low molecular weight fluid, etc.; 2)Optimize minimum viscosity of fracturing fluid, then optimizing the corresponding pumping rate; 3)Optimize combination of fluid and proppant type and size according new mathematical model; 4) Try acid-fracturing during pad stages so as to minimize formation damage and fracture damage to obtain an optimized propped profile.
The technology has been put in to filed application in 45 wells, the performance of post-fracturing is very remarkable with the daily oil rate being 14m3/d increased more than 32.2% that of the past well stimulation, and it has a great significance in the near future.
Floating Mud-Cap Drilling Application in Exploration Well Accelerate Reaching Target Depth While Drilling Surface Hole
Authors: Muis Arvi R. , Hidayat Andri M. , Irawan Fikri 
Published: August 2016

Abstract
The objective carbonate interval in Parigi formation often experiences total loss circulation and migration of gas to surface after losses circulation experienced which hardly to be controlled with conventional technique. In depth preparation is highly required before penetrating this carbonate formation which is known for its loss-kick cycles while drilling. Because of the secondary porosity, drilling through the highly vugular Parigi formation results in total loss circulation of the drilling fluid. Wellbore hydrostatic column instantly decreased while drilling into the loss formation.
Utilization of Rotating Control Device (RCD) eliminates the Non-Productive Time (NPT) associated with time consuming mitigation of loss – kick cycles. RCD enables close loop drilling system when the bearing assembly is installed, capping the annulus and creates pressurize-able wellbore annulus system. Completed with 18-3/4″ bottom flange, the RCD was connected on top of 21-1/4″ Annular BOP intermediated with a flange adapter. Parigi limestone was to be drilled with 17-1/2″ bottom hole assembly to be able setting casing13-3/8″ successfully.
The Mud-Cap drilling system passively seals the annulus at any time by employing the RCD bearing assembly, complementing the existing secondary well control system to prevent the direct gas release to the rig floor. During the operation, unexpected gas release were occurred while wiper trip, however the RCD was successfully kept the pressure away from the rig floor and allowed the driller to strip down the drill string back to the bottom. Details of RCD deployment and setup procedures will be elaborated in this paper.
Continuous Operation Model in Multi-Well Pad W202H2: First Shale Gas Factory in Block Weiyuan, SW China
Authors: Ming Liu 
Published: August 2016

Abstract
In recent years, the development of shale gas has been paid more attention in China. Since the first shale gas well drilled in 2009, the number of shale gas wells is increasing rapidly. In 2015, the yearly gas production reached 210 BCF. As a matter of fact, China is experiencing an era of shale gas boom regardless of the low oil price in the international market.
From 2010, to speed up the development process, four national shale gas demonstration plots were built, including CW plot, JSB plot, ZT plot, and YA plot. After the JSB plot obtained the first breakthrough in 2013, CW plot took its important step in the development of shale gas resources in 2015. Due to the topographic inequality of Sichuan basin, the multi-well pad was used to solve the problem of well deployment difficulty. In 2013, continuous operation including batch drilling, factory fracturing and gas testing for 13 wells has been successfully conducted in tight-gas reservoir, which provides valuable experience for the shale gas operation model.
This paper aims to describe the continuous operation model and its effectiveness in the pad W202H2 of block Weiyuan (CW plot), located in the southwest China. To improve the cost effective production while maintaining a responsibility for health, safety, and the environment is the most important advantage of the model. To improve the operation effectiveness, two rounds of 3-well zipper fracturing are conducted. The cooperation among water supply, fluid mixing, sand supply, and pumping ensures the continuous fracturing. A total fluid and proppant injection of 189023m3 and 6677m3 for 102 stages/299 clusters are completed in 44 days, which makes the best efficiency record in China. Compared with the single well fracturing, the economic benefit is highly improved and about 6 million dollars are saved. Moreover, the continuous operation model shows a large effective stimulated reservoir volume (ESRV), which is in accordance with the micro-seismic monitoring result.the maximum daily production and wellhead pressure reaches to 32×104m3 and 44MPa, respectively.
Post Well Pore Pressure Analysis Facilitated by Managed Pressure Drilling
Authors: Brands Allan W. , Rajabi Mehdi Mir 
Published: August 2016

Abstract
Real-time managed pressure drilling (MPD) data is analysed post drilling for the purpose of identifying ‘formation pressure events’ which are quantified to define the actual wellbore formation pore pressure (PP) profile.
MPD software allows the operator to maintain a desired bottomhole pressure (BHP) by application of surface backpressure (SBP) at the choke manifold. The system closely monitors; flow in, flow out and BHP within the closed system to identify minor influxes to the wellbore which are controlled before they can propagate in size by automatic application of SBP. Utilisation of MPD technology in combination with downhole pressure monitoring, allows for a series of micro-influxes to be analysed to map a formation PP profile.
MPD facilitates the analysis of the PP by performing dynamic PP testing. The PP can be accurately determined by reduction of BHP until a miniscule influx is detected in a controlled manner by MPD.
MPD allows BHP to be maintained close to the perceived PP. Maintaining this BHP will result in a diminishing overbalance when drilling into overpressured zones. The diminished overbalance will result in a micro-influx which will be identified by MPD and controlled by application of SBP, while knowledge of the PP is obtained.
Acquisition of data from micro-influx events induced or otherwise, documents the PP regime as it is drilled allowing post well interpretation to build a detailed picture of the PP. A case study is presented which illustrates how a number of PP events can be analysed post well to map the PP of a hydrocarbon bearing reservoir.
This paper illustrates how application of MPD not only provides enhanced safety benefits from a well control perspective by early kick detection, but allows the operator to gather critical formation pressure data, as the formation pressure profile is mapped while drilling.
Real-Time and Wireless Monitoring of Wellhead and Conductor Fatigue
Authors: Gauthier Steven 
Published: August 2016

Abstract
Subsea wellhead and conductor systems can be subject to high fatigue damage during drilling operations, sometimes requiring to be monitored in real-time. Existing online monitoring systems use cables strapped the exterior of the riser, to display the data topside, leading to a number of potential issues.
In order to address these issues, Pulse Structural Monitoring has developed a wellhead and conductor fatigue monitoring system using acoustic data transmission. The monitoring system consists of motion sensors installed on the BOP/LMRP. Each sensor has the ability to continuously measure response without intervention for up to a 9 months. The data from each data logger is transferred in real-time to a topside processing unit via an acoustic transmitter on the LMRP.
The paper describes the requirements from Oil & Gas operators taken into account in the design followed by the different phases of testing using the Technology Readiness Level (TRL) method that the new acoustic data logger underwent including sea trial. As this type of system already exists, using cables to communicate the data topside, this new technology had to bring the advantage of not having a cable while being able to transmit and display data fast enough to be considered real-time, while maintaining a long enough battery life to last one to several campaigns. The acoustic system is proven to be able to overcome the high noise levels created during drilling operations and communicate continuously and reliably without being affected by surrounding noise or other wireless communication systems up to today's and tomorrow's deep water depth.
The paper presents a new and now proven way of monitoring wellhead fatigue in real-time and wirelessly enabling Oil & Gas operators to take informed decisions, minimising disconnect periods and collecting well integrity data, while avoiding issues related to subsea cables.
The World's First Gate Valve Milling on E-Line Returns Well to Production Faster and Safer
Authors: Al-Mulhim Abdallah , Al-Shawly Alaa , El-Zefzafy Ibrahim , Al-Atwi Mohammed , Al-Beheiri Faisal , Azmey Adel , Chehabi Wissam 
Published: August 2016

Abstract
Stuck wellhead gate valve at surface offers and demand an extreme well integrity operation. Subsequently; well intervention operation needs more attention and might become more complex using conventional milling techniques. Conventional milling techniques have also fail to meet required well control or found to be lengthy and costly operation.
The world's first novel gate valve milling operation using e-line has been performed safely and successfully in Saudi Arabia. Saudi Aramco; land based oil producer well; located in Southern Area of the Ghawar field; was shut-in due to malfunction of Tubing Master Valve (TMV) on closed position for Signal Stack-Up X-Tree. 3,000 BOPD and well accessibility were locked with expected 1,600 psig as shut-in wellhead pressure underneath the stuck valve gate is the case.
The objective of this paper is to provide a safer and faster operation solution for milling gate valve that would adhere to the operator's well integrity safely and well control polices. This paper will describe detailed job design, operational steps of this novel milling operation, and other technical considerations that resulted in the successful execution of challenging operation.
A Local Mechanical Model of Down-Hole Tubular Strings and its Amendment on the Integral Model
Authors: Huang Wenjun , Gao Deli 
Published: August 2016

Abstract
A new concept "local down-hole tubular model", which provides a more sophisticated description of tubular string deflection from local perspective, is proposed to overcome the shortcomings of the conventional integral model. The coupling effects of three factors including wellbore configuration, buckling mode and connector are studied in the local model. Firstly, an equivalent beam-column model is proposed to reduce arbitrary wellbores except vertical wellbores into horizontal wellbores. Thus, the tubular behaviors in arbitrary wellbores can be simplified into that in vertical and horizontal wellbores. Secondly, the two-dimensional (2D) lateral deflection, three-dimensional (3D) inter-helical buckling and intra-helical buckling of tubular strings with and without connectors under four contact cases, namely no contact, point contact, wrap contact and full contact, constrained in horizontal and vertical wellbores are studied. Meanwhile, the fitting formulae which depict the effects of connectors on critical buckling loads, contact forces and bending moments are calculated. At last, the integral model is further amended based on the results from the local model. The results show that the effect of wellbore configuration can be equivalent to additional tubular string weight. Connector parameters are closely related to buckling modes, critical buckling loads, post-buckling deflection curves, bending moments, contact forces, etc. The combination of integral and local models, namely the amended integral model, establishes a more sophisticated description of axial force, torque, bending moment, contact force and buckling mode distributions along the entire tubular string.
Governance and Guidelines for Remote Health in Asia
Authors: Teo D. 
Published: August 2016

Abstract

Objectives/Scope
With the rapid growth of the energy, mining and maritime industry in Asia, there is an increasing awareness of the health conditions for workers and engineers in remote areas. This has led healthcare practitioners to focus on developing the standardisation of medical services for all staff that live and work in remote sites. The objective is to educate the engineers and other professionals in the industry on the recommended approach to build a guideline which can be used for managing remote site medical clinics and services in Asia.

Methods, Procedures, Process
Through the contribution and discussion with subject matter experts from various fields of remote health in Asia, a set of guidelines has been built. It serves as a guide for healthcare practitioners to implement medical services in remote sites, including but not limited to offshore, mining and other remote installations. The guidelines are based on the healthcare system of several Asian countries, namely: Singapore, Thailand, Malaysia, Vietnam, Indonesia, China and India. The risk assessment for remote site installations and the standardisation of healthcare practitioner's competency which is based on their knowledge, skills and experiences are also addressed.

Results, Observations, Conclusions
Measurement on the remoteness of a site is regarded as the key factor and standard to identify the medical support needs. However, simplistic reliance on one key factor could lead to potential costly mitigations such as special medication, diagnostics, resuscitative methods and enforcement of timely medevac. In some scenarios, timely medevac is simply not possible due to geographical distance, or lack of air medevac resources.
Therefore, using the measurement on the remoteness of the site to the nearest shore-based hospital may not be the best method to set the standard, as it limits the understanding of the risk levels of each specific site. It is also not applicable to some remote installations, particularly Asia.
It is proposed that a risk assessment methodology which evaluates the risk level on a case by case basis should be adopted in Asia. Through this, a healthcare practitioner can study the past data for each site, based on the impact of the hazard and the likelihood of an incident occurring at the particular remote site.
Consequently, the healthcare practitioner could identify the needs and recommend the appropriate medical service.
This results in the avoidance of litigation, reduction of lost-time injury, and unnecessary medical costs. Novel/Additive Information: The novelty of this paper is in the ability to help oil and gas companies mitigate the Health risks at remote locations specifically in Asia. Previous guidelines have been developed from the perspective of the North Sea market and applied universally, however there is now a clear need for specific guidelines for this region.
Advanced Dynamic Drillstring Modeling Delivers Efficient Underreaming and Rathole Elimination Solutions
Authors: Sonny S. , Soh A. , Najmi N. F. , Ivan L. , Jagathrakshakan K. , Morris L. 
Published: August 2016

Abstract
While planning a wildcat exploration well, an operator faced formation depth uncertainty as a result of poor seismic imaging as well as limited offset pore pressure and fracture pressure data. A steep pressure ramp was anticipated at some depth below surface casing, and casing design included a 16-in liner to secure this interval. To properly evaluate and understand the lithology and pressure while drilling would require high-quality LWD data, but it was also essential that the liner and casing could be fully run to the bottom of the hole. Underreaming near the bit while drilling would compromise the LWD data, but underreaming above the LWD tools would not enable the casing to be fully run to bottom. Two hole-enlargement-while-drilling (HEWD) BHAs with the option for rathole elimination (RHE) were proposed and enabled these objectives to be efficiently achieved without compromise. A combined HEWD and RHE BHA is not new in the industry, but it is challenging in large hole sizes. With multiple cutting structures in the BHA, drillstring dynamics become complex. The resultant vibration and shock can lead to diminished drilling performance, or even failure of BHA components.
A prejob finite-element analysis (FEA) modeling simulation was used to investigate the dynamic drilling behavior of the initially-planned BHAs. The simulation results from initial BHA design predicted high vibrations. A BHA optimization analysis was then conducted to determine the most favorable BHA configuration for effective LWD tool placement and minimized vibration issues, taking into account the BHA geometry and stabilization points, cutting structures, and formation type. The simulation results from the final BHA exhibited a significant reduction in shock and vibration levels. Suitable drilling parameters were identified, and hydraulics simulations were performed to ensure that both the HEWD and RHE underreamers could be reliably actuated.
The operator implemented the recommended BHAs, cutting structures, and parameter roadmaps on both the 17-in × 20-in and 14¾-in × 17½-in sections, and the solution successfully drilled 501-m and 605-m intervals, respectively. Each interval was drilled and enlarged in a single trip. Both HEWD BHAs exhibited low levels of vibration during the original underreaming, enabling quality LWD data to be obtained. After maximizing section depth, the HEWD underreamer was deactivated and the RHE underreamer activated, enabling the rathole to be underreamed and subsequently the liner and casing strings run fully to the bottom of the hole.
Advanced dynamic drillstring modeling can simulate downhole drilling conditions, enabling improved prejob planning and thus more efficient drilling operations. Proper design of HEWD and RHE BHAs can help the operator efficiently maximize the quality of LWD data while drilling.