bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pillar Fracturing Technique Application in the Algerian Desert for Well Production Enhancement
Authors: Forno Luca Dal , Allal Mohammed A. , Gheraissa Mohammed , Kateb Mahmoud , Mohammed Omar 
Published: January 2018

Abstract
Rhourde Attar field in the northwestern Algerian desert is exploited from the Lower Devonian sandstone. This formation is composed of sandy and silty-sandy intervals with thin, shaly intercalations. The reservoir is characterized by very porous sands (20 to 25%), which also show relatively low permeability (1 to 15 md). Deposition of chamosite minerals reduced permeability, without reducing primary porous volume. This paper proposes a pillar fracturing technique designed to overcome formation constraints and enhance production.
Beyond the moderate petrophysical properties related to rock diagenetic history, the reservoir is suffering from a gradual depletion trend, limiting the oil production rate and driving the bottomhole operating condition below the bubble point. It was proposed that placing a highly conductive fracture stimulation treatment could possibly help overcome these constraints. An oil producer well of the field was selected for the first application of a pillar fracturing technique combined with a resin to consolidate the created channels within the fracture.
The pillar fracturing technique allows conductivity maximization through the placement of open channels within the stabilized proppant pillars. This unique fracture geometry is achieved by pulsing clean fracturing fluid stages alternated with slurry stages that carry the propping agent. The proppant pillars are then stabilized with the addition of a specifically designed resin to coat the proppant as it was being pumped throughout the entire fracturing process. Proper candidate selection, accurate fracture modeling, and employment of proven pumping equipment are crucial elements for achieving a successful and safe intervention. The implementation of this stimulation technique provided positive results both in terms of operational execution and final well performance.
Additionally, this technique mitigates the risk of undesired screenout by reducing the proppant volume compared to a conventional job. Moreover, the initial production of the well revealed a significant improvement while the long-term performance showed a stabilized trend. Based on these outcomes, the use of this technique could face a fast increase within the Algerian market, considering also possible refracturing interventions on older wells.
Development and First Application of Monobore Openhole Expandable Clad in the Tarim Oilfield
Authors: Guo H. J. , Xu B. G. , Yin H. W. , Liu Z. T. , Lv M. J. , Wang J. L. 
Published: January 2018

Abstract
The application of the first open-hole expandable liner in Tarim Basin has demonstrated the value of the numerical models developed to assess the effects of the required large expansion ratio, particularly on connection sealability. This paper discussed the modeling, the assessment of the highly expanded thread form, lab testing to confirm its performance, and the field application.
The expandable casing was required to span 127 m of open-four hole to prevent the closure of a section of mobile mudstone. The 10 ¾ in. in originally planned across the interval could not be run due to the tight hole, and the expandable was successful in allowing the well to continue below the mudstone in an 8 ½ in. hole. The concern was the effect of the large expansion ratio on the sealability of the connector. ABAQUS was utilized to build a model which was then calibrated with ten groups of expansion tests with a variable diameter cone. Tests included both internal and external pressure loads.
Expansion ratios of 20.2% were achieved in the lab without tube failure or thread leakage at the loads expected in the Tarim Basin application. The casing was successfully installed and expanded in June 2016, and drilling continued to the planned total depth. The success of the modeling in lab and field applications creates confidence that the model itself can be used to develop designs for other loading conditions in other applications with minimal full-scale lab testing. While there is an additional opportunity in the Tarim Oilfield, confidence in a generalized model will encourage engineers to assess other opportunities.
The ability to predict expansion stresses and sealability are also seen as the first step for the operator in the development of a monobore system that provides full pass-through and a casing-to-casing seal that can be deployed economically in the low-cost Tarim Basin operations.
Smart Loss Circulation Materials for Drilling Highly Fractured Zones
Authors: Mansour A. Khaled , Taleghani A. Dahi 
Published: January 2018

Abstract
Lost circulation materials (LCMs) have played an essential part when trying to decrease the heavy financial costs resulting from mud loss and non-productive time. However, the LCMs used in the field today still have drawbacks such as failure to work in a high pressure - high temperature environment, damage to production zones, inability to seal big fractures and plugging the drilling tools. In this paper, we introduce a new smart lost circulation material made out of anionic shape memory polymers and it does not have the disadvantages that the LCMs experience in the field today. The smart LCMs has the ability to be programmed to change in shape, bridge and expand when stimulated by a specific temperature. A fully coupled simulation is developed to test the sealing efficiency of the newly introduced smart LCMs. Various particle size distributions and fracture sizes were used to further understand the properties of the smart LCM. The proposed smart LCM shows efficacious sealing of fractures and could be the next smart solution for lost circulation.
A Novel 8000m Rig and its Application for Ultra-Deep Well Drilling in Submountain Region
Authors: Chen Peng , Fang Taian , Zhou Zhixiong , Wang Junjie , Yuan Xubo 
Published: January 2018

Abstract
A new type of the 8000m drilling rig ZJ80/5850 has been researched, manufactured and successfully applied for ultra-deep well drilling in the submountain region of China's Tarim oilfield. The new kind of rig was developed to deal with the problems of load incapacity of drilling with the 7000m rig and high cost of drilling with the 9000m rig in ultra-deep well drilling.
Deep or ultra-deep well drilling operations in the piedmont area were predominated by the 7000m rigs. In order to tackle the situation of ultra-deep well drilling in the piedmont zone in Tarim oilfield, primary technical parameters of the rig had been enhanced with maximum hook load capacity 5,850kN, 52MPa high pressure rig pumps were equipped, compacted strands high tension wirelines were first used, derrick structure of the rig was optimized, and high strength material was selected for the main structure. Thereby a perfect general technical scenario of rig and associated techniques were formed.
The Tarim basin in northwestern China featured complex geological conditions and deep buried reservoirs. The potential risk of the 7000m rig safety as drilling around 8,000m ultra-deep wells emerged and the rig accident occurred as the big-size casing was deeply set due to the bare weight of the casing exceeding the load capacity of 4,500kN. Drilling efficiency has significantly been enhanced after 22 rigs of the type 8000m rig were applied for ultra-deep well drilling in the Tarim oilfield in less than three years. The 8000m rig has become prevailing equipment for drilling operations in the submountain region of Tarim. The procurement cost of roughly USD2.5bln was cut down per set of the 8000m rig as compared to that of the 9000m rig. The daily drilling rate per rig was saved by 20%-30%. Total amount of USD36.8bln for integral cost of drilling was saved per rig per year.
The optimization of the 8000m rig parameters and advanced associated technologies have filled in the gaps of China's rig standards and perfected the standard series of China's rigs. R&D of the new type 8000m rig was a result of market demand and satisfied by clients for the exploration and production of ultra-deep buried reservoirs.
Successful Implementation of Multi-Modal, Self-Assembling, Self-Degradable and Environmentally Friendly Solids Particulates as Diverter in Acid Stimulation Treatments in Carbonate Reservoirs
Authors: Malik Ataur R. , Asiri Mohammed A. , Ogundare Tolulope M. , Khalifa Mohamed 
Published: January 2018

Abstract
This paper focuses on the evaluation of novel diversion technology based on self-degradable solids particulates that were applied in the complex carbonate reservoirs. The well performance results were compared in this paper between wells stimulated with novel and conventional diversion technologies as part of the evaluation.
The continued dependence on fossil hydrocarbons and the need to increase oil and gas production present solider challenges to more effectively stimulate marginal reservoirs with cost effective and improved technologies. In carbonate reservoirs, this challenge to maximize production comes from the increase in the stimulated reservoir volume. Diversion techniques in acid stimulation treatment in carbonate reservoir plays a major role in improving the stimulated reservoir volume. A typical acid stimulation design includes the diverter stages in between acid stages with the objective of both temporarily plugging the stimulated intervals and directing the treatment fluids to other untreated intervals and enhancing far-field diversion. It is necessary that these diverting materials are completely degradable and non-damaging to the reservoir.
High temperature, high stress, pressure depletion, sour environment, and heterogeneity make certain carbonate reservoirs very complex and several diversion techniques have been tested in complex carbonate reservoirs over the last decade. In fact, enhancement in diversion technique for carbonate reservoirs is continuously being explored by the local well stimulation network team. Because of extreme reservoir complexities and heterogeneities in multifaceted carbonate reservoirs, it is critical to select an appropriate diversion technique along with optimum acid blends to redirect stimulation fluids from treated intervals to untreated intervals. The post-stimulation high resolution temperature logs and productivity index analysis indicated that wells stimulated with a novel diversion technology exhibited enhanced production due to its ability to produce more uniform distribution of acid along the net pay intervals.
The novel diversion technology consists of multi-modal, self-assembling, self-removing, and environmentally friendly particles, presented in dry solid form to provide quicker and stronger redirection of fluid-flow paths by using the particle-bridging technique and sealing-off the width near the fracture's tip. More effective stimulation is achieved by branching fractures from subsequent stages as a result of far-field diversion.
Scaling and Completion Fluid PH Effect on Sandstone Formation Damage
Authors: Hamzaoui Bilel , Moajil Abdullah M. 
Published: January 2018

Abstract
The effectiveness of completion fluids prior to the actual cost and risk of implementation is critical to evaluate. High salinity/ high pH brine can cause formation damage to sandstone formation following well completion operations. The magnitude of damage depended on the fluid/fluid and fluid/rock proprerties.
This work demonstrates the experimental results to evaluate the effect of completion fluid pH on sandstone minerals and the compatibility with the formation water.
Solids and core plugs analysis were conducted using XRD. ICP analysis of three completion fluid samples was performed to determine its elemental composition. Fluid/rock interactions assessment were conducted using zeta potential analysis.
Scaling of calcium sulfate andsalt self-precipitation occurred when high pH completion fluid was mixed with formation water. Zeta potential results showed that sand stone minerals were less stables at high pH.
Date Pit-Based Additive as Density Reducing Agent in Underbalanced Drilling
Authors: Adewole Jimoh K. , Najimu Musa O. , Adewunmi Ahmad A. 
Published: January 2018

Abstract
A new drilling fluid additive has been developed for application as density reducing agent. The additive can be used for preparing lightweight drilling fluid formulation for use in underbalanced drilling. The preliminary results obtained from the performance analysis revealed that the date pit - based additive possesses some potential to be used as a density and formation fluid flow control agents in water-based drilling fluid. The addition of 5ml (ca 1.40 vol%) of the additive to bentonite drilling fluid formation decreased the density of the fluid by 21%. The effect of the additive on other drilling fluid properties such as fluid loss and filter cake thickness were also evaluated.
Fiber Glass Casing Design, Planning and Installation Experience in Observation Wells
Authors: Al-Oqab Mohammad , Kaushik Preyankar , Ahmad Abuzar Tanweer , Kumar Subodh 
Published: January 2018

Abstract
Monitoring and continuous reservoir evaluation is very important aspect of a well-planned Waterflood program. Valuable well and reservoir information needs to be obtained during the course of waterflood operation, which helps in determining oil recovery and decide on the future strategy of the Waterflood program. Keeping this in view, KOC decided to drill some observation wells completed with cemented fiberglass casing for monitoring the flood performance in sandstone and carbonate reservoirs in two different fields. The use of fiberglass casing facilitates the application of some deep induction logging tools for measuring the changes in formation properties behind the casing. Vital information such as oil saturation change during waterflood operation, vertical sweep efficiency and arrival time of different fluid fronts can be determined from these log surveys in fiberglass casing.
Cemented fiberglass casing and liners were used over the years globally mainly for observation wells and in some cases for highly corrosive injection wells. However, the use of fiberglass tubulars as casing or liner needs careful planning for its safe deployment and longer life. The casing policy, depth, drilling mud weight and logging requirement mainly dictates the selection of a particular size and thickness of fiberglass casing. Special cementing program needs to be formulated due to its lesser strength properties (collapse, burst & axial rating) compared to normal steel casing. They can be run either as complete fiberglass casing/liner or as combination string with steel casing depending on the zone of interest and purpose of deployment.
KOC has successfully deployed 9-5/8" size fiberglass casing as combination string with steel casing in more than 20 vertical/deviated observation wells. The depth of deployment ranges from 4500 ft. in sandstone formation to around 8000 ft. in carbonate formation. Additional care was taken while preparing/ planning the cementation to prevent failure of the fiberglass casing while cementing across deeper formations.
This paper describes in detail the design and planning of the observation well completed with fiberglass casing. Different scenarios leading to selection of particular size of fiberglass casing supported by StressCheck application and cementing technique are presented. Some special consideration related to cementing and running in equipment, which needs careful attention. The paper with the deployment cases will be a quick guide to engineers.
Evolution of Drilling Dynamics Measurement Systems
Authors: Akimov O. , Hohl A. , Oueslati H. , Reckmann H. 
Published: January 2018

Abstract
Continuous development of drilling technology has enabled the oil and gas industry to drill deeper and more complex well paths. Drilling dynamics measurements have been the dominant contributor to rate of penetration maximization, overall drilling optimization and downhole assembly reliability assurance for more than three decades.
A consequence of today's complex downhole assemblies and well paths are higher downhole forces and vibrations. These conditions require more quality drilling dynamics information than before for safe and efficient drilling. Driven by this demand, new developments in downhole and surface equipment have made available larger amounts of drilling dynamics data with higher sample rates. In parallel, development of reliable high-speed telemetry allows the high-resolution drilling dynamics data to be utilized on surface to deliver answers while drilling. These developments were made possible due to the recent advent of high-performance downhole-capable electronic technologies, as well as the availability of increased computation power for signal processing at the rig site.
This paper describes improvements in the drilling dynamics measurement systems to overcome the challenges imposed by deeper and more complex wells. Gathering, processing and transmitting drilling dynamics data at high rates introduces challenges due to tighter downhole sensor requirements, the required digital signal processing power, amount of available memory, electronics temperature tolerances and telemetry requirements. Optimized hardware design, signal processing and enhanced telemetry sequences and methods are answers to these challenges, to ensure the adequate performance of drilling dynamics measurement systems. These improvements allow a fast response to new drilling conditions, the adjustment of drilling parameters to changes in formation, and a rapid evaluation of drilling performance. This enables field personnel to make decisions focused on drilling optimization, and these case histories are added to advance drilling optimization best practices.
The drilling dynamics measurement system described in this paper has been successfully run in challenging fields in the North Sea and Middle East. Compared with offset runs, the system has significantly increased data quality and sample rate and provided, in addition to industry-standard-measurements, unique measurements for the identification and mitigation of high-frequency torsional oscillations. Examples of the improved capability and operational performance are provided.
This paper also highlights changes necessary to further improve drilling dynamics measurement systems for evolving real-time drilling optimization needs.
Step Change in Wellbore Positioning Accuracy
Authors: ElGizawy Mahmoud , Aklestad Darren , Lowdon Ross 
Published: January 2018

Abstract
A survey program is designed for every well drilled to meet the well objective of penetrating the target reservoir and to avoid colliding with other offset wells. The selection of the wellbore survey tools within the survey program are limited to the current accuracy available to the industry. A newly developed wellbore survey technique has proven to have superior accuracy compared to the current standard measurement-while-drilling (MWD) surveys with in-field referencing and multi-station analysis (MSA).
In almost every drilling bottom hole assembly (BHA), there is an MWD survey tool to survey the wellbore while drilling. Accuracy of the MWD surveys has been improved over the years by correcting potential error sources such as misalignment of the survey package from the borehole, drillstring magnetic interference, limited global geomagnetic reference, and gravity model accuracy. This new positioning technique takes the accuracy of MWD surveys to the next level by combining surveys from two independent survey packages. The second survey package is installed inside the rotary steerable system (RSS). Surveys from both packages are retrieved while drilling.
Results have been obtained from multiple runs worldwide, enabling comparisons between the new technique and standard MWD surveys from both an enhanced accuracy and true wellbore placement point of view. A proposed error model is based on both the theoretical improvements in accuracy and the empirical proof from the data analyzed. The improved accuracy while drilling assures higher confidence that the well placement will maximize reservoir production and avoid collision with nearby offset wells.
In reservoir sections, the wellbore survey accuracy limits the lateral spacing, and this constrains the reservoir production. In top and intermediate sections, wellbore survey accuracy limits the well plan, and this affects how close the well can be drilled in proximity to other offset wells. This directly impacts the complexity of the directional work and the cost per drilled foot. The new technique unlocks the potential to significantly improve the wellbore positioning accuracy.
First Multilateral Well Worldwide with an Intelligent Completion System and Openhole Acid Stimulation
Authors: Hart Sofiri , Saggaf Hatem 
Published: January 2018

Abstract
The Middle East has long been a pioneer in innovation in drilling and completion technologies for multilateral wells. It was here that the first1 multilateral tool (MLT) on coiled tubing was used to access and stimulate each openhole lateral in a trilateral well. Over the years, several2-4 applications of this and similar technologies have been made. In each instance, a conventional upper completion system was installed.
In a multilateral well with a conventional upper completion and an openhole lower completion, there is no independent flow control from each lateral. Because of this, production is not optimized to account for differences in the production rate or reservoir quality of each lateral. For a well with an upper intelligent completion system (ICS), independent control of flow from each lateral is possible through the use of surface controlled flow control valves (FCVs). This feature addresses the shortcomings of the conventional upper completion mentioned earlier.
The challenge in performing an acid stimulation of each openhole lateral in a well with an ICS is the inability to access any of the laterals after the ICS has been installed. Current technologies do not afford this option and designs in the pipeline do not have field proven applications.
This paper chronicles a novel attempt at acid stimulating each openhole lateral of a trilateral well in a carbonate reservoir. It includes the installation of the ICS in the same well. The challenges, results, learnings and future courses of action are documented in what should provide a template for continuous improvement.