bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Design Methodologies to Develop Mechanical Intervention Tools with Unique Emergency Release Feature to Operate Subsurface Barrier Valves
Authors: Balasubramanian Ganesh 
Published: March 2020

Abstract
Subsurface barrier valves such as a formation isolation valves (FIVs) isolate the formation from the production bore after the first perforation and the lower completion has been installed. This enables installation of the upper completion and in some cases multiple perforation runs before the well starts producing. During this time, they protect the formation from fluid loss and pressures by acting as a bidirectional fluid barrier. In addition to reduced rig time, a key advantage of FIVs is reduced intervention costs. FIVs can be openend and closed multiple times as required, mechanically with an intervention tool such as a primary shifting tool (PST) (Fig. 1). The conveyance method for PSTs can be on coiled tubing, work string, perforating string, or wireline (using a tractor and stroker) to open and close FIVs. PSTs then must reliably engage and release from shifting profiles in the FIVs to operate the valve and release from the profile after successful valve actuation.
Hence design of the PST is critical for relaible FIV operation. In the event of an emergency where the shifting profile in the tool is unable to release from the engaging profile in the FIV, it is critical to have an emergency release feature inherent in the PST that can enable release of the tool yet not damage the FIV. A novel methodology was developed to design PSTs to enable emergency release if required, through controlled plastic deformation at loads below work string shear limitation. This methodology also avoids fracturing of PST components as free-hanging pieces could be caught in the wellbore while pulling out the tool from the well after emergency release.
A Game Changing MWD Tool for Next Generation CTDD
Authors: Kante Adame , Fahim Ud Din Syed Muhammad , Saenz Eduardo , Shetty Kiran 
Published: March 2020

Abstract
The objective of the project was to expand the operating envelope of the Measurement while Drilling (MWD) tool in the coiled tubing directional drilling Bottom Hole Assembly (BHA) to improve its reliability in harsh environments, maintainability, temperature range and measurements for overall longer runs and better service delivery.
A new concurrent development approach was used for managing the product's lifecycle from defining the customer's need, selecting the best technical solution, developing and thoroughly testing the product to confirm it meets its requirements and to finally manufacture it efficiently before its release to the field. Several rigorous technical and management reviews were held to enable focused decisions toward the efficient delivery of a reliable, manufacturable and maintainable product with minimal total cost of ownership. The tool includes a robust gamma ray sensor, Direction & Inclination (D&I) package to enable real time geo steering decision-making, pressure and temperature sensors to monitor the inner and well conditions and a load cell to measure both the axial and torsional loads. A set of electronic boards used for communication, power and acquisition, have been fully qualified to operate in the harshest drilling conditions. In addition, several surface software components were developed for real time data display and reporting.
The reliability for the MWD tool was increased 4 folds based on the results from a time period of 12 months of intensive drilling up to 167C. We managed to set field records for both the longest single runs for footage and time improving average downhole utilization by 60%.
Unique Electronically Activated Nonexplosive Wireline Cutter Provides Safe and Reliable Cuts on Largest Range of Slickline and Wireline Cables
Authors: Hillier Jill , Sabanegh Nader , Nicol Mark 
Published: March 2020

Abstract
The electronically activated nonexplosive wireline cutter drops from surface to sever slicklines and cables when a toolstring becomes stuck downhole. The cutter is activated via an electronic timer and trigger module.
The cutter was originally designed to cleanly cut slickline and wireline cables ranging from 0.105 in. to 5/16 in. As wireline cables become larger and more complex, the need for a more robust wireline cutter was needed to cut cable with outer diameters as large as 0.59 in.
Preprogrammed countdown times and optional custom programming capabilities support target depth and activation assurance without reliance on explosives or impact against the stuck toolstring to make a cut. The features of the unique electronically activated nonexplosive wireline cutter are outlined and several case studies presented from onshore and offshore operations.
Downhole Ultrasonic Thickness Measurements for Inspection of Casing: A Comparison of Log Derived Modeled Casing Wear, Surface Measurements, and Calculations for Casing Integrity
Authors: Abouganem Stephens Alberto , Akindipe Olutunde J. , Leong Chew Y. 
Published: March 2020

Abstract
Drillpipe wear is a concern of operators when the tubular and/or the main bore of the well will be reused, for example in a sidetrack, or when the casing will be pressure tested. Drilling of long reach wells also creates a surface or intermediate casing wear problem. The fear of possible casing wear dictates the location of gas lift mandrel, which greatly affects well production and productivity. The objective of this paper is to show how downhole measurements have been compared with surface measurements of casing thickness to validate their use on casing wear models. Downhole tubular thickness measurement with ultrasonic tools is a well-known technique that has been used for many years in the oil and gas industry. The use of such downhole measurements varies from calculating burst/collapse rating to validating tubular integrity for reuse. These ultrasonic thickness measurements are done by computing the resonant frequency of the casing azimuthally in several samples sized around 1 in., then converting the resonant frequency to a thickness using known art and/or proprietary algorithms. The casing thickness can also be measured in a surface laboratory. The thickness of newer casing is measured in the laboratory to confirm its specifications and create a baseline. Similar measurement can also be done on retrieved casing to inspect their well and verify wear prediction models. The surface measurements are of much higher resolution and azimuthal sampling than a downhole measurement tool.
The results of downhole thickness measurements and those of surface thickness measurements performed in a laboratory facility are compared and will be presented. The study highlights the match between the two types of measurements, the impact of a-priori knowledge of steel velocity, and comparing the log calculated burst pressure ratings to an actual laboratory measurement on joints. These joints have both downhole and surface measurements. When the tubulars are manufactured with corrosion resistant alloys, the steel acoustic properties deviate from the standard steel which the downhole measurements are based upon. The difference on acoustic velocities of the materials will be reflected on the thickness measurements of both downhole ultrasonic tools and surface laboratory measurements. Whereas surface laboratory measurements can be calibrated in-situ, downhole measurements need a priori knowledge of the acoustic properties. This paper describes the range of acoustic properties and how they affect the log derived thickness. Also, the accuracy of the downhole measurement is compared with the surface measurement when the steel properties are known
Using Fluidic Oscillation Technology with Coiled Tubing to Cleanout Scale from a High-Pressure/Extreme-Temperature Well Beyond the Limits of an HPHT Motor: A Case Study from the UK North Sea
Authors: Ermakov Konstantin , Hampson Richard , Barclay David 
Published: March 2020

Abstract
This paper explains some of the challenges that are faced with coiled tubing (CT) bottom hole assemblies (BHA) when working in high-pressure/extreme-temperature (HP/ET) environments with unfavorable fluids and how these challenges were successfully overcome.
CT was selected as a contingency to operate a downhole completion isolation valve with a hydraulically activated shifting tool and impact tool. By design, this type of valve is operated using a sequence of pressure cycles, working only when a certain differential pressure is present across the valve. CT became the primary option when problems occurred during the pressure cycle operation. After shifting the valve, wireline operations also encountered problems when they hung up prematurely and could not pass a depth in this new HP/ET well with an open hole completion. Initial investigations found that a blockage of swarf combined with settled oil-based mud and calcium carbonate fallout was the source of the problem. Three attempts with two different types of high-pressure/high-temperature (HP/HT)-rated motors ended unsuccessfully after only short exposure to the extreme downhole temperatures.
As an alternative solution, a fluidic oscillation tool was run on the CT in an attempt to clear the blockage. This method resulted in a successful cleanout followed by an acid treatment of the open hole section in a single run with the same BHA.
Conformance Sealant Slurry Squeeze to Stop Production
Authors: Brown James , Hassan Amr , Hall Matthew 
Published: March 2020

Abstract
Highly depleted zones could represent a major challenge for well completion or intervention because of several issues, including high losses, crossflow, and low fracturing pressure. However, nowadays, there are several options to treat or isolate depleted zones to allow further well completion or intervention.
A major North Sea operator had plans to perforate in Formations B and C formation on a well after determining that they could still be at original pressure and separated from the already producing and depleted Formation A. Following a second perforation run on wireline, tool lift was measured. This tool lift correlated with crossflow from the newly perforated zone to the existing depleted A zone, and did not allow the perforation guns to reach the required total depth (TD).
The service company proposed a three-dimensional rigid gel system comprised of an organically crosslinked polymer (OCP) conformance sealant with particulates. The system, deployed with coiled tubing (CT), was designed to be squeezed into the near-wellbore matrix. The depth of penetration is controlled by adjusting the particulates concentration in the gel system and squeeze volumes. Fluid volumes were calculated to achieve 6 in. of formation penetration. Laboratory tests suggested that the polymer would cure after 12 hours at bottomhole static temperature (BHST) and excess in the wellbore could be jetted out using CT.
A total of 30 bbl of gel system were pumped in two separate batches, with partial isolation and reduction in fluid loss achieved after the first 20-bbl batch. An additional 10-bbl batch was pumped to help ensure isolation. Pressure tests and fluid loss after the second treatment indicated almost 90% of the open perforations in the depleted zone were isolated with minor losses observed compared to a loss of more than 80% in the wellbore before the treatment. The operator was satisfied with the results and, after jetting the excess gel from the wellbore, perforation operations were performed successfully.
This paper discusses in detail the job execution, including CT and pumping equipment which were selected specifically for this operation, and including cleaning and pumping, bottomhole assemblies, running in hole procedures, the pumping schedule; fluid recipe used, and laboratory testing performed to define curing time and rheology.
This paper also highlights challenges faced during execution caused by high depletion, techniques used to overcome these challenges, and methods used to evaluate the success of the isolation while CT is still in hole.
Complex Abandonment Operation Simplified through the use of High Performance, High Expansion Plug Technology
Authors: Laguado Maria Camila , Suarez Oscar Leonardo , Murphy Robert Allan , Mora Edgar , Rinconn Luis , Maya Diego Martín 
Published: March 2020

Abstract
On April 2017, the well Cupiagua H42 located in Colombia was suspended due to lifting capacity which were caused by low gas-liquid ratios (GLR) despite a 5" × 4-1/2" velocity string had been hanged below Down Hole Safety Valve (Insert Valve) after original completion was run in order to improve the lifting capacity. Others technical approaches for well recovery and recoverable volumes were evaluated, for example Coiled Tubing gas lift technology and conversion to a gas injector. However, economic evaluations of the different approaches considered, indicated only marginal results and low probability of operational success due to a fish at the top of the 4-1/2" OD liner. Taking all these fact into consideration, the decision was to abandon the well in accordance with Colombian Governmental regulations.
The Achieving of this requirement would be difficult due to the 3.25-in. restriction in the well, and the necessity of isolation inside the 7-in. Production Liner.
Using a Multilateral Entry System and Slow Rotating Wash Tool to Increase Efficiency of Lateral Cleanouts with Coiled Tubing
Authors: Crawford Rob , Wright Adam 
Published: March 2020

Abstract
With the rising industry trend in multilateral completions, there is a cost and productivity benefit resulting from increasing the efficiency of entry and cleanout of lateral wellbores. Cleanout operations are proven to improve production from laterals and there exists a variety of different options of wash tools on the market. Among these wash tools, slow rotating wash tools have been proven to be more efficient during cleanout operations when compared to traditional wash nozzles. A new and commercially viable approach combines a hydraulically activated multilateral entry system with a slow rotating wash tool to increase the efficiency of downhole lateral cleanouts while utilizing technology and tools that are on the market today.
This paper presents an improved method of lateral cleanout with a system consisting of a high torque indexing tool for orientation, a hydraulic knuckle joint with a bleed port to generate a pressure drop indication, a shearable choke sub to enable high rate cleanout and a rotating wash tool with modified centralizer body and interchangeable nozzles. For well cleanout efficiency, the articulated length of the toolstring and the centraliser OD can be optimised to ensure the slow rotating wash tool nose is as centralised as possible.
The system was set up in an example job scenario and a mock cleanout performed to simulate operations. The job demonstrated the operation of the multilateral entry system and the confirmation pressure changes expected to be witnessed during the job. High rate cleanout rates were achieved by shearing the choke sub and considerations for setup and configurations discussed. The need for lateral entry and efficient cleanout will only increase as more laterals require stimulation intervention and this paper presents an option for providing a cost-effective, efficient cleanout operation.
Hybrid Electro-Optical Cable for Coiled Tubing Logging and Interventions
Authors: Segura Jordi , Trummer Sascha , Grisanti Maria , Varkey Joseph , McCabe Jeff , Hofacker Mark , Fancio Caio , Pathak Devesh , Keong Azwan , Vingen Sindre 
Published: March 2020

Abstract
This study presents the evolution of downhole fiber optics to a new hybrid electro-optical cable for coiled tubing (CT) applications. The optical fibers enable optical communication and distributed measurements such as distributed temperature and acoustic sensing. The electrical layer delivers continuous surface power to downhole tools, eliminating typical battery limitations such as temperature, operating time, and safety concerns. The electrical layer also enables cable telemetry operation of wireline tools.
The hybrid cable is composed of several layers: an inner tube protecting the optical fibers, a layer of low-DC-resistance conductors to deliver high voltage downhole, an insulator, and an outer tube that is exposed to the fluids in the CT pipe. This complex cable is packaged with an outer diameter of only 1/8 in. to maintain maximum flow rates achievable through the pipe. Surface and downhole equipment used with the cable are designed to accommodate electro-optical terminations separating the conductors and optical lines.
The cable has been manufactured, tested, and installed in CT pipes. The surface and downhole equipment has been designed and certified to operate in both land and offshore environments and tested with multiple families of tools: well intervention tools instrumented with pressure, temperature, depth control, and load sensors; wireline tools, including pulsed neutron generator and flow profiling tools; a multilateral re-entry tool; and an electrically actuated multiple-set retrievable plug.
Over 20 runs and 1,000 hours of operation have already been completed without any power or telemetry loss. The system has saved 160 hours of operation time in Middle East from the implementation of the hybrid cable single-reel solution on four jobs that formerly required two CT strings. In the Norwegian continental shelf, the system saved between 24 hours and 32 hours in a single job by eliminating trips to surface to replace the batteries.
This new hybrid cable and its associated surface and downhole system provide a single solution for interventions, distributed measurements, and logging. Altogether, they pave the way for significant improvements in well intervention efficiency and open new avenues for more complex and demanding operational workflows.
Parameter Prediction Method for Submarine Cuttings Piles in Offshore Drilling
Authors: Sun Baojiang , Zhang Zhi , Wang Zhiyuan , Pan Shaowei , Wang Ze , Chen Wang 
Published: March 2020

Summary
The cost of offshore drilling operations can be significantly reduced by discharging drilling cuttings into the seabed. However, this leads to accumulation of cuttings piles on the seabed near the drilling site. A certain thickness of cuttings piles changes the original trend of the seabed terrain undulation condition, thus bringing potential safety hazards to the underwater installation of production manifolds. Moreover, the interaction between cuttings and ocean currents near the cuttings piles causes the geometric shape of cuttings piles to evolve over time, which makes it more difficult to accurately predict their characteristics. On the basis of the force analysis of cuttings, considering the effects of cuttings properties (cutting size, density) and ocean-current velocity on the geometric characteristic evolution of the formed cuttings piles, a continuous model for describing the evolution of the returned cuttings piles is established in this study. This model can quantitatively characterize the functional relationship between characteristics of cuttings piles and relevant parameters (current velocity, cutting size, evolution time), and predict the location and geometry characteristics of the cuttings piles evolving into a stable state in ocean currents. Comparing the measured data in laboratory experiments and at an offshore drilling field, the relative error of the model amounts to less than 10%, which demonstrates its rationality. Simulation results show that there will be significant changes in the geometry of cuttings piles before and after the evolution, in which the intensity is correlated with current velocity and cuttings size, and cuttings piles might even split into several parts under certain conditions. The simulation and analysis of the transport and deposition of cuttings returned from the wellhead on the seabed is highly significant for the guide and optimal design of underwater production manifolds.
Pneumocystis jirovecii Colonization and Its Association with Pulmonary Diseases: a Multicenter Study Based on a Modified Loop-Mediated Isothermal Amplification Assay
Authors: Xue Ting , Ma Zhuang , Liu Fan , Du Weiqin , He Li , Wang Jinyan , An Chunli 
Published: March 2020

Abstract
Background Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungal pathogen and the role of its colonization in pulmonary diseases has become a popular focus in recent years. The aim of this study was to develop a modified loop-mediated isothermal amplification (LAMP) assay for detection of Pneumocystis jirovecii (P. jirovecii) DNA amongst non-HIV patients with various pulmonary diseases and use it to examine the prevalence and assess the association of P. jirovecii colonization with clinical characteristics of these diseases. Methods We modified the previously reported LAMP assay for P. jirovecii by adding real-time detection. This method was used to detect P. jirovecii colonization in pulmonary samples collected from 403 non-HIV patients with various pulmonary diseases enrolled from 5 hospitals in China. We determined the prevalence of P. jirovecii colonization in 7 types of pulmonary diseases and assessed the association of P. jirovecii colonization with clinical characteristics of these diseases. Results The modified LAMP assay showed no cross-reactivity with other common pulmonary microbes and was 1,000 times more sensitive than that of conventional PCR. Using the modified LAMP assay, we detected P. jirovecii colonization in 281 (69.7%) of the 403 patients enrolled. P. jirovecii colonization was more common in interstitial lung diseases than in chronic obstructive pulmonary disease (COPD) (84.6% vs 64.5%, P < 0.05). Patients with acute exacerbation of COPD had a higher prevalence of P. jirovecii colonization compared to patients with stabilized COPD (67.4% vs 43.3%, P < 0.05). P. jirovecii colonization was associated with decreased pulmonary function, increased levels of 1,3-β-D-glucan and C-reactive protein, and decreased levels of CD4+ T-cell counts (P < 0.05 for each). Approximately 70% of P. jirovecii colonized patients had confections with other fungi or bacteria. Conclusions We developed a modified LAMP assay for detecting P. jirovecii . Our multi-center study of 403 patients supports that P. jirovecii colonization is a risk factor for the development of pulmonary diseases and highlights the need to further study the pathogenesis and transmission of P. jirovecii colonization in pulmonary diseases.