bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trailblazing Unconventional Exploration: Out-of-the-Box Solutions Result in Elimination of NPT and Faster Delivery of Challenging Unconventional Horizontal ERD Wells
Authors: Hegazy Mohamed , Sharma Sunil , Fares Khaled , ElBatran Ahmed 
Published: October 2018

Abstract
Drilling unconventional horizontal extended reach wells has always been challenging; coupled with geological and drilling challenges of an exploratory field, they present the perfect combination for non-productive time (NPT). To maximize production, it is paramount to reach the whole reservoir and extract hydrocarbon resources efficiently. Moreover, to increase profits, the well should be drilled in minimal operating time, which in turn reduces operating expenses. This paper presents a detailed study and outline of neoteric practices used to drill four such wells in an unconventional field that resulted in the elimination of NPT and reduced drilling and completion time to less than one-third.
Thirteen wells have been drilled under an unconventional gas exploration project since 2007 with a historical average drilling and completion time of 95 days (and best record of 60 days). Numerous challenges associated with the field (i.e., loss of circulation, hole instability, stuck pipe, bit balling, casing held up) led to an average NPT of 40 days. To eliminate NPT and improve operational efficiency, a detailed study of the offset wells' drilling and mud programs was conducted with the operator. After an in-depth review and analysis, a revised mud program was adopted containing a holistic approach to encounter the challenges faced in offset wells, as they were all interconnected. The use of a novel rate of penetration (ROP) enhancer and proprietary software for precise hydraulics management resulted in improved ROP, elimination of bit balling, and excellent hole cleaning. A modified bridging strategy, using software simulations validated by lab testing and changes in sweeping procedures to avoid wash out and removal of filter cake, cured losses successfully and improved overall hole condition. A totally new composition for mud mixed on location in the event of total losses and use of innovative polyamine inhibitor for reactive formations eliminated hole instability and stuck-pipe incidents. Implementing these customized solutions, combined with precise operating strategy, led to zero NPT and a reduction of average drilling and completion time to 29 days; this saved a total 245 days and an overwhelming cost savings in drilling fluid services cost for the four wells drilled to date.
This paper discusses the outstanding performance achieved while using the existing setup by modifications in operational procedures and inventive techniques. It also describes cost effectiveness, overall performance-based results, and challenges while implementing the strategies. A detailed
comparison of all the challenges that occurred while drilling and the proper troubleshooting steps are also discussed. Finally, the paper compares the existing results with previous drilling techniques, which may help operators with the future development of their respective fields.
Case Study: Innovative World's Slimmest Coiled Tubing Tractor for Stimulation of Extended Reach Wells
Authors: Saeed Abubaker , Saiood Hussain , Arsalan Muhammad , Moore Bruce 
Published: October 2018

Abstract
In extended Reach wells, existing coiled tubing (CT) technologies were unable to pass narrow downhole restrictions and reach target depth (TD) for stimulation operations. Overcoming current limitations in extended reach downhole tools resulted in the development and field use of a slim, compact, and record-setting high pull-force tractor that enables rig-less stimulation, thereby maximizing production and cost effectiveness.
A development project evaluated multiple tractor design concepts, yielding a new generation of an ultra-slim (2-1/8 inch OD) and high pulling force tractor. Exhaustive shop, yard, and flow loop testing verified the tractor's ability to reliably pull in both cased and open hole, employ multiple layers of failsafe technologies, and facilitate rigging up with simpler and less expensive operations. A series of wells with increasing depth and difficulty were used to demonstrate the technology for field use.
The design process verified that the new generation tractor efficiently moves in an accordion-like motion, grips the roof of the hole with an eccentric gripper assembly, and is powered by differential pressure created by pumping fluid down the CT centerline. Shop and Flow Loop testing verified that the eccentric gripper automatically orients itself to engage the high side of the hole, thereby providing an excellent and debris-free surface for traction. Flow Loop testing verified that tractor's ability to circumnavigate high dog leg severity well bores. In one field demonstration, the tractor successfully passed a 2.44 inch restriction, conveyed coiled tubing 2400 feet past lockup reaching well TD of almost 21,400 ft, and averaged 15 feet per minute while running in hole. The benefits of this technology come in the successful operation of a tractor that produces up to 3500 lbs. pulling force, collapses to 2-1/8 inch outside diameter, and operates in 6-1/8 to 7-1/2" inch diameter open hole.
The paper summarizes the research and development of this innovative world's slimmest coiled tubing tractor for stimulation of extended reach wells. It discusses a recent field trial operation including the yard and function surface tests to prepare for this field trial. The paper also explains in details how this technology was successfully deployed, in addition to the broad implications resulting from production engineers having this technology in their tool box, which will permit them to ensure cost efficient operations, maximize production, and will enable rig-less intervention of restricted extended reach wells all over the world.
Optimization of water consumption of hydraulic fracturing treatment by utilizing recycled flowback fluidse
Authors: Al-Arnous Ahmed , Al-Qahtani Nasser , Al-Sugair Bader , Al-Arfaj Ayman 
Published: October 2018

Abstract
As the hydraulic fracturing activities are dramatically increasing in Saudi Arabia, the demand of fresh water supply for stimulation jobs is also growing. Conventional acid/proppant fracturing stage normally acquires 80,000 to 100,000 gallons. In areas where water source is over a large scattered distance, delivering water to locations becomes logistically complex. Therefore, a solution to overcome the dilemma of fresh water scarcity is vital to preserve the resources and save the cost on the long-term.
This paper analyzes the solutions implemented to preserve the fresh water utilization in fracturing applications in the kingdom and the other proposed solutions in the upcoming future. Two methods have been approved successfully into preserving fresh water consumption and alternate the utilization of fresh water resources: Sea-water Nano filtration, and CO2 fracturing fluid. Both applications have been implementing in Gauwar field into gas bearing zones as an acid or proppant treatments. However, delivering sea water from water injection plant, then filtrate it makes the process even more complex than utilizing a fresh water sources. Moreover, such a practice was not economically viable and requires an infrastructure for long term plan. In addition, remote areas and scattered gas fields won't benefit much of this alternative. On the other hand, utilization of CO2 as a base fracturing fluid reduced the usage of fresh water as a current solution. Thus, it is still depending on the formation compatibility and the CO2 quantities in hand.
As a result, a new solution is proposed to overcome the fresh water scarcity especially with the expansion of gas fracturing operations in the kingdom. The need to find a sustainable cost effective alternative is crucial, such as Recycling Flowback fluid to be reused as a base fluid for the next stages on the same well. The process will save fresh water resources, transportation of water from the source to the desired well in the front end and waive the need to treat the flowback fluid and dispose it into the waste disposal area on the back end.
In the gas fields of the kingdom, most of onshore gas wells require fracturing operations to economically produce. More than 50 % of the new wells acquire 3-5 stages to be hydraulically fractured in order to produce commercially and sustain production. In the meantime, 40-60% of fracturing fluid returns back during the flowback operation after each stage where 10% of that fluid is mixed with gel and the rest is a gel-broken fluid. The concern is filtering the fluid after the gel is broken to simplify the process.
In summary, this paper comprehensively reviews the benefit of using a robust fracturing fluid that can utilize 100% produced/flowback instead of freshwater for fracturing operations; that should become the norm as we move into a more environmental friendly paradigm.
Geomechanical Property Computation from Digital Rock Models and Comparison with Core Measurements
Authors: Saad Bilal , Jin Guodong , Ali Shujath Syed , Alshanqaiti Elham 
Published: October 2018

Abstract
Rock mechanical properties are critical to reduce drilling risk and maximize well and reservoir productivity. This paper present a methodology of predicting mechanical properties (Young's modulus and Poisson's ratio) from 3D rock models generated using laboratory measurements or downhole logging data. The 3D rock model provides the microstructure and boundary to simulate rock elastic properties. Mechanical properties are computed from rock models using the finite element method.
Laboratory measurements were conducted on four Berea sandstone samples to determine the mechanical properties for comparison and other properties as input in rock modeling, such as bulk and grain density, porosity, mineralogy, and grain-size distributions. Numerical results from rock models generally match the core measurements of the corresponding samples. The methodology proposed in this study could potentially be applied downhole for predicting the mechanical property profile along the wellbore, as all input parameters to generate rock models can be derived from logging measurements.
Nanoparticle-based chemical treatment for preventing loss circulation
Authors: Wagle Vikrant , Kalgaonkar Rajendra , Al-Yami Abdullah S. 
Published: October 2018

Abstract
This paper provides development of a novel nanoparticle-based chemical treatment composition for its potential use a loss circulation material. The novel loss circulation material is based on a delayed activation chemistry to gel up an environmentally friendly nanomaterial based dispersion. The chemical treatment composition comprises of two major components viz. nanoparticle based dispersion and a chemical activator. A major advantage of the activator used to gel up nanoparticle-based dispersion is its ability to place the treatment composition in to the target zone before the nanoparticle based dispersion gels up thus avoiding premature setting of the treatment fluid. The newly developed system can be used effectively up to 300°F. The gelation times were evaluated at different temperatures up to 300°F. The effects of pH and different concentration of activators on gelation times of the new treatment fluid has also been studied. The effectiveness of the newly developed composition as a loss circulation treatment was also evaluated by performing permeability plugging tests to test the plugging capacity of this novel system.
The novelty of the newly developed treatment composition is to have a controllable gelation time under a variety of downhole conditions to allow accurate placement of the treatment fluid inside the wellbore without premature setting of the fluid. It was shown that the gelation time of the treatment composition could be controlled by adjusting the concentration of the activator. The system gives a predictable and controllable pumping time, ranging from a few minutes to several hours at over a wide range of temperatures. This is an important advantage of as it allows the treatment composition to remain pumpable for sufficient time for placement and develops the network structure that leads to gelation, over a predictable period of time. The set gel, which appears as a crystalline solid, could remain homogenous and stay in place thereby preventing loss circulation.
Advances in near-surface characterization and deep imaging with smart DAS upholes
Authors: Bakulin Andrey , Golikov Pavel , Smith Robert , Erickson Kevin , Silvestrov Ilya , Al-Ali Mustafa 
Published: October 2018

Abstract
A smart distributed acoustic sensing (DAS) uphole system is proposed that utilizes a cost effective, permanently installed fiber as a seismic sensor embedded in the shallow subsurface. Using this system, uphole velocity surveys for near-surface characterization can be acquired with a single shot by recording all depth levels simultaneously. Dense grids of on-demand smart DAS upholes produce more accurate long-wavelength statics than conventional approaches, reducing uncertainty in the interpretation of low-relief structures. Connecting multiple upholes with a single fiber enables seismic surveys to be acquired with buried vertical arrays. These can provide robust images of the deeper subsurface like surface seismic, but with much improved accuracy due to the elimination of most of the near-surface complexities. The system comprising a carpet of surface shots and a dense grid of smart DAS upholes provides a complete dataset for near-surface characterization as well as imaging for oil and gas exploration of low-relief structures.
The proposed smart DAS uphole acquisition scheme was successfully tested on an onshore field in Saudi Arabia. The field test demonstrates the validity of the components and the entire system. Smart DAS uphole data was found to be of excellent quality, while recorded seismic data with buried vertical arrays showed clear reflection signals and produced images of the deeper subsurface.
This paper presents the smart DAS uphole system for near-surface characterization and deep imaging, including a discussion of the processing results from the data acquired during the field tests. We show how the novel acquisition system can be used in the petroleum industry to decrease the risks associated with the exploration of low-relief structures.
A Novel Emulsified Acid for Deep Wells Stimulation: Rheology, Stability, and Coreflood Study
Authors: Ahmed Musa , Sultan Abdullah , Qiu Xiangdong , Sidaoui Ziad , Ali Al-Amri Ahmad 
Published: October 2018

Abstract
The main objective of matrix acidizing is to create deep channels(wormholes) that bypass the damaged zone around the wellbore, which eventually, will increase the productivity or injectivity of the well. HCl-diesel emulsified acid is used to achieve that goal as well as other objectives such as prevention of tubing corrosion. The cost of HCl-emulsified acid could be lower by reducing the cost of either the surfactant (emulsifier) or the continuous phase (diesel). Hence, in this study, a low-cost, more efficient emulsified acid is proposed, with cheaper solid stabilizer (nanoparticle) instead of surfactant, and less expensive continuous phase; waste oil instead of diesel. Rheology, stability and coreflooding experiments were performed at high-pressure high-temperature (HPHT) of a typical reservoir conditions in the Middle East. This study addresses the feasibility of a novel waste oil emulsified acid system in acid stimulation treatment. In particular, rheology and stability of the emulsion and reactivity with limestone reservoir rock at HPHT were investigated. The reactivity was carried out through a series of core flow experiments at HPHT and compared with the conventional diesel emulsified acid. Stability experiments were conducted at 375 °F. Coreflood experiments were conducted using Indiana limestone 12″ cores and 1.5 in diameter. The initial permeability of the cores was in the range of 2-4 md. The pressure and temperature were 3000 psi and 275 °F, respectively. Four injection rates were used 0.5, 2, 5, and 10 ml/min. For better comprehension for resulted wormhole characteristic from both stimulation fluids under investigation, the CT-scan image for the Indiana limestone cores after injection of both waste oil and diesel emulsified acids were performed and analyzed through a high resolution imaging and visualization software.
From the laboratory results, the novel waste oil emulsified acid system showed a good potential as a stimulation fluid. For instance, it achieved lower pore volume of acid to break through (PVBT) compared to both conventional diesel emulsified acid and plain HCl. Moreover, diesel emulsion presented a better performance at lower injection rates whereas waste oil emulsion performed superiorly at higher rates. Thisindicates that, diesel emulsion is still better in terms of stimulation efficiency, however, waste oil emulsified acid still could be recommended in acid stimulation since it has low cost and acceptable performance. Furthermore, CT scan analysis shows that waste oil emulsified acid was capable of achieving narrow, branch-free, and deep wormhole which are the desired characteristic for any potential stimulation fluid.
The novelty of this work comes from the fact that waste oil emulsified acid performance for carbonate acid stimulation has not been addressed before and hence this work to fill in the gap.
The impact of hydraulic fracturing on the deliverability of multilateral wells at dry gas reservoirs
Authors: Ahmed M. Elmuzafar , Elnuaim Sami , Abdulazeem Ahmed 
Published: October 2018

Abstract
The use of multilateral wells became significant in the recent years for both oil and gas development projects due to its maximum productivity resulting into fewer dollars per SCF development cost. However, there is a common mistake during the planning phase of these complex wells. They usually overestimate/underestimate the production from these complex well due to the lack of analytical well productivity estimation models in the literature which would require expensive numerical modeling. This paper investigates the effect of hydraulic fracturing on the productivity of this kind of wells and other factors like the anisotropy and lateral length as well as the fracture conductivity.
22 different scenarios were investigated to study the effect of different variables on the deliverability of the multilateral well. The base case scenario was built using ECLIPSE simulator. The effect of the lateral length and the number of laterals were studied then the fracture effect introduced to the base case starting from 1 stage fracturing up to 8 stage fracturing. Furthermore, the reservoir anisotropy and the fracture conductivity was explored. All these data sets were analyzed and combined using regression techniques to get one mathematical model that can predict the productivity in a simplified procedure. Vogel-type was used to get the final productivity model.
Based on the results, it was found that the most significant parameters that affect the study are reservoir anisotropy, and the fracture width. It was observed that changing the number of fracture stages is significant specially in the 8 laterals case as compared to the 4 and 6 lateral cases respectively. In addition, changing the number of lateral while holding the number of fracture stages constant showed small effect on 1 and 3 stage fractures compared to the significant effect in the 2 and 4 stage fracture. Changing the total length of the laterals plus the main horizontal stem also have great influence in the productivity. The effect of the fracture width and reservoir anisotropy which was found to be the most affecting parameter.
The mathematical model is simple to be used for quick estimation of the productivity relationship multilateral dry gas wells with very good accuracy in a way that save a lot of effort and time. And also can be implemented in simulator to save a great computational effort. The model was tested using different cases and found to give reasonable results with small average error.
Investigating the effect of hydraulic fracturing in the pressure transient response for multilateral wells in dry gas reservoirs
Authors: Ahmed M. Elmuzafar , Abdalla Mohamed 
Published: October 2018

Abstract
Using pressure transient testing is very useful to identify reservoir properties, such as permeability, and reservoir size. However, it can also be used as an evaluation tool to test the success of the fracturing process as well as identifying the fracture properties such as conductivity and size. This paper presents an investigation of the fracture properties and their effect on pressure and pressure derivative signature in multilateral wells at dry gas reservoir as well as the effect of the number of laterals, length of laterals and reservoir anisotropy.
The base case scenario was built using ECLIPSE simulator. More than 20 scenarios were used to generate the data and use the early production region as the drawdown feed data. different scenarios were investigated to analyze the pressure derivative signature and hence study how hydraulic fracture stages will appear in the curve and how can we utilize that to characterize our fracture. The effect of the lateral length and the number of laterals were studied then the fracture effect introduced to the base case starting from 1 stage fracturing up to 8 stage fracturing. Furthermore, the reservoir anisotropy and the fracture conductivity was explored.
The results of this study can be used as qualitative method to judge the success of the fracturing job by comparing the response before and after the fracturing. It was noticed that increasing the number of lateral and the length of lateral shifted the pressure derivative curve down. However, increasing the fracture stages while keeping the number of lateral constant affected only the early region.
Well testing techniques can be extended to study the complex geometry of multilateral well especially when hydraulic fractures are induced. It will be a great benefit to the industry to test their work with a quick method without the need to use downhole monitors.