Subsea Multiwell High-Flow-Rate Riserless Acid Stimulation Campaign With Two- Vessel Approach: A Comparative Case Study

2021 ◽  
Author(s):  
Irma Kusumawati ◽  
Birger Heigre ◽  
Hunter Whitfield ◽  
Samuel Bremner ◽  
Andrea Sbordone ◽  
...  
Keyword(s):  
High Pressure ◽  
Control System ◽  
Pressure Support ◽  
Operational Efficiency ◽  
Lessons Learned ◽  
High Rate ◽  
Comparative Case Study ◽  
Operating Efficiency ◽  
Injection Wells ◽  
Well Control

Abstract This paper describes the utilization of a riserless light well intervention (RLWI) vessel with well control system and flexible downlines to execute a re-stimulation campaign on subsea injection wells located in the Norwegian Continental shelf in the summer of 2019 and 2020. A riserless light well intervention (RLWI) vessel with well control system and flexible downlines was used in combination with a stimulation vessel. The objective of each campaign was to increase injectivity in the wells with high-rate acid treatments. The lessons learned from the 2019 campaign were applied to the 2020 campaign, resulting in reduced health and safety exposure, and improved operational efficiency. Analysis of the treatments and their impact on injection and field pressure support was conducted to assess the effects of these improvements and provide insights for how the treatments can be applied to vessel stimulation in general. In each campaign, the RLWI vessel was connected to the subsea asset, and a dedicated stimulation vessel provided stimulation fluids via a high-pressure flexible hose connected between the two vessels. Both campaigns saw high treatment pump rates of up to 60 bbl/min with low-pH crosslinked gel fluids, 28% hydrochloric acid, and diverters in the form of ball sealers and rock salt. Hose deployment methodologies between the two vessels differed in the two campaigns. The 2019 campaign employed a conventional transfer utilizing the marine crane on the RLWI vessel to lift and lower the hose into a preexisting hanger. Learnings from this operation led to the development and use of a winch pull-in method in which the hose connection was accomplished with a hot stab connector on the RLWI vessel, eliminating human intervention and the use of the crane. The 2019 and 2020 campaigns successfully stimulated five and six subsea injection wells, respectively, and realized post-stimulation improvement in injection rates of 135%. One year of field monitoring from the first campaign shows pressure support benefits with improvements in production throughout the connecting area of the field. The winch pull-in method of hose deployment between the vessels achieved time improvements of 8 hours per stimulation treatment. In addition, the added flexibility of not needing to be within crane reach gave the operation extended working weather limits. The overall result was a significant improvement in operating efficiency between the 2019 and 2020 campaigns. The operations showed how high-rate stimulation can be achieved on subsea assets with the use of an RLWI and stimulation vessels. Detailed analysis of the operational efficiency of each campaign was performed, and the improvements from one campaign to the next documented. The winch pull-in method is a new way of high-pressure hose transfer that can be applied to future stimulation vessel operations to improve operational safety and efficiency.

A Cost-Effective Stimulation Workflow Unlocks New Perspectives for Matrix Acidizing in Openhole Horizontal Tight Carbonate – A Case Study from West Kuwait

2021 ◽  
Author(s):  
Salem Al-Sabea ◽  
Milan Patra ◽  
Abdullah Abu-Eida ◽  
Nasser Al-Azmi ◽  
Mohammad AlEidi ◽  
...  
Keyword(s):  
High Pressure ◽  
Cost Effective ◽  
Lessons Learned ◽  
Carbonate Reservoir ◽  
High Rate ◽  
Distributed Temperature Sensing ◽  
High Permeability ◽  
Study Results ◽  
Tight Carbonate ◽  
The Impact

Abstract The Mishrif formation in west Kuwait is a tight carbonate reservoir having low oil mobility. It is fractured and heterogeneous with wide variation in porosity ranging from 10 to 25%, matrix permeability of about 0.1 to 10 md, and 20°API oil. Production tests and geomechanical study results have revealed that productivity is mostly from the high-permeability matrix and critically stressed fracture networks. Recently, the Mishrif development has been dominated by horizontal wells to maximize reservoir contact and enhance productivity. However, a challenge in such openhole completion is the stimulation strategy requiring effective diversion technology due to the uneven acid distribution along the lateral section. To address those challenges, a novel engineered workflow has been implemented relying on distributed temperature sensing (DTS) to assess the fluid coverage across the openhole section. Results enable identifying high- and low-intake zones, segmenting the uncased section into intervals requiring different levels of stimulation, and making informed decisions regarding diversion requirements. The intervention was conducted in two stages. Coiled tubing (CT) was the selected fluid conveyance method on the first stage given its capacity for more controlled fluid placement, and high-rate bullheading stimulation was selected for the second stage. During the treatment, multiple challenges were faced, mainly driven by a high-permeability streak identified by the DTS near the heel of the lateral. The CT stimulation procedures were modified on the spot, and measures were taken to minimize the impact on the thief zone, which included a combination of diversion techniques, such as high-pressure jetting, dual injection, and pumping of a near-wellbore nonreactive diverter, which is composed of a customized blend of multimodal particles and degradable fibers to minimize fluid leakoff into the high-intake zone. Likewise, real-time downhole telemetry was crucial throughout the CT stimulation because it allowed the highest injection rate possible below the preset pressure limits, continuous monitoring of downhole dynamics along the intervention, and optimal actuation of the high-pressure jetting tool. Upon completion of the CT stimulation, a second DTS log was carried out to evaluate the fluid coverage and effectiveness of the diversion strategy, enabling further adjustment of the bullhead stimulation program. This stimulation workflow implemented in west Kuwait represents a cost-effective alternative to stimulate openhole tight carbonates. This study brings new perspectives for treating complex reservoirs in the region, and shares lessons learned for future interventions.

Optimization Applied to Buzios Flexible Riser Systems and Subsea Layout

2021 ◽  
Author(s):  
Vinicius Gasparetto ◽  
Thierry Hernalsteens ◽  
Joao Francisco Fleck Heck Britto ◽  
Joab Flavio Araujo Leao ◽  
Thiago Duarte Fonseca Dos Santos ◽  
...  
Keyword(s):  
Deep Water ◽  
Technology Use ◽  
Capital Expenditure ◽  
Lessons Learned ◽  
Internal Diameter ◽  
Flexible Riser ◽  
Flexible Pipe ◽  
Injection Wells ◽  
Gas Field ◽  
Field Development

Abstract Buzios is a super-giant ultra-deep-water pre-salt oil and gas field located in the Santos Basin off Brazil's Southeastern coast. There are four production systems already installed in the field. Designed to use flexible pipes to tie back the production and injection wells to the FPSOs (Floating Production Storage and Offloading), these systems have taken advantage from several lessons learned in the previous projects installed by Petrobras in Santos Basin pre-salt areas since 2010. This knowledge, combined with advances in flexible pipe technology, use of long-term contracts and early engagement with suppliers, made it possible to optimize the field development, minimizing the risks and reducing the capital expenditure (CAPEX) initially planned. This paper presents the first four Buzios subsea system developments, highlighting some of the technological achievements applied in the field, as the first wide application of 8" Internal Diameter (ID) flexible production pipes for ultra-deep water, leading to faster ramp-ups and higher production flowrates. It describes how the supply chain strategy provided flexibility to cover the remaining project uncertainties, and reports the optimizations carried out in flexible riser systems and subsea layouts. The flexible risers, usually installed in lazy wave configurations at such water depths, were optimized reducing the total buoyancy necessary. For water injection and service lines, the buoyancy modules were completely removed, and thus the lines were installed in a free-hanging configuration. Riser configuration optimizations promoted a drop of around 25% on total riser CAPEX and allowed the riser anchor position to be placed closer to the floating production unit, promoting opportunities for reducing the subsea tieback lengths. Standardization of pipe specifications and the riser configurations allowed the projects to exchange the lines, increasing flexibility and avoiding riser interference in a scenario with multiple suppliers. Furthermore, Buzios was the first ultra-deep-water project to install a flexible line, riser, and flowline, with fully Controlled Annulus Solution (CAS). This system, developed by TechnipFMC, allows pipe integrity management from the topside, which reduces subsea inspections. As an outcome of the technological improvements and the optimizations applied to the Buzios subsea system, a vast reduction in subsea CAPEX it was achieved, with a swift production ramp-up.

Comparative assessment of the dynamics of the incidence of pulmonary and etraulmonary tuberculosis in St. Petersburg for half a century of observation

MedAlliance ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 6-14
Keyword(s):  
Control System ◽  
Incidence Rate ◽  
Extrapulmonary Tuberculosis ◽  
High Rate ◽  
Tb Control ◽  
Complete Restoration ◽  
Third Stage ◽  
High Level ◽  
Clinical Awareness ◽  
Positive Effect

This article describes the results of comparative analysis of the dynamics of incidence of pulmonary tuberculo-sis (TBP), extrapulmonary extrarespiratory tuberculo-sis (TBER) and respiratory extrapulmonary tuberculosis (TBREP) in St. Petersburg (Leningrad) from 1970 to 2019. Throughout the 50 years of observation, epidemiological situation for TBP, especially for TBER, hasmuch improved, with incidence of the latter going down 30 times. Five stages (decades) were identified, within which the factors demonstrate practically the same impact, the growth rate of indicators was calculated for each stage (the value of indicators at the beginning of each stage taken as 100%).The first stage was a simultaneous reduction in the inci-dence rate in all categories of TB localization against the background of socio-economic factors positive effect and organization of effective and comprehensive an-ti-TB measures. In the second stage (1980ies, a period of growing socio-economic problems), the positive dynam-ics of TB incidence stopped and switched to stabilization at a low level. Indicators became more volatile, while TB dynamics by localization more and more desynchro-nized. Тhe third stage (1990iеs, a period of social and economic crisis) was char-acterised by a sharp increase of TB incidence, especially TBREP, with a switch to stabi-lization at a high level. The fourth stage (2000 through 2009, the beginning of TB control system restoration) demonstrated the indicators’ dynamics desynchroniza-tion: the incidence of TBP and TBREP has stabilized, and TBER continued to decline. The fifth stage (2009 through 2019, complete restoration of TB control system) showed a steady trend of incidence rate reduction and return of uniformity in incidence rate of various localizations.There is no increase in the proportion of extrapulmonary TB expected for the incidence decline. TBER incidence had been declining in most stages, with the exception of the 90ies, which could be explained by substandard work in identifying patients, and the rarity of TBER etiological verification. It is necessary to raise the clinical awareness of narrow specialists and general practitioners in the di-agnostic problems associated with TBER.The coincidence of the rate of TB incidence decrease in main localizations in the 1970ies and 2010s proves that a comprehensive state strategy to combat tuberculosis can provide a high rate of TB incidence decrease in various social layers with positive social and economic conditions of life of the population.

scholarly journals EVOLUTION OF THE QUALITY OF HIGH-PRESSURE VALVES DURING THE PERIOD OF THEIR INTENSIVE DEVELOPMENT

2021 ◽  
Vol 05 (01) ◽  
pp. 04-10
Author(s):  
Sabir Babaev ◽  
Ibrahim Habibov ◽  
Zohra Abiyeva
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Machine Building ◽  
High Rate ◽  
Performance Criteria ◽  
Gas Industry ◽  
Evolution Of Technology ◽  
Intensive Development

Prospects for the further development of the oil and gas industry are mainly associated with the development and commissioning of high-rate fields. In this regard, the production of more economical and durable equipment by machine-building enterprises, an increase in the level of its reliability and competitiveness, as well as further improvement of technological production processes, is of paramount importance. The evolution of technology in a broad sense is a representation of changes in designs, manufacturing technology, their direction and patterns. In this case, a certain state of any class of TC is considered as a result of long-term changes in its previous state; transition from existing and applied in practice vehicles to new models that differ from previous designs. These transitions, as a rule, are associated with the improvement of any performance criteria or quality indicators of the vehicle and are progressive in nature. The work is devoted to the study of the evolution of the quality of high-pressure valves during the period of their intensive development. Keywords: technical system, evolution of technology, high-pressure valves, shut-off devices, gate.

Fully predictive Common Rail fuel injection apparatus model and its application to global system dynamics analyses

2016 ◽  
Vol 18 (3) ◽  
pp. 273-290 ◽  
Author(s):  
Alessandro Ferrari ◽  
Pietro Pizzo
Keyword(s):  
High Pressure ◽  
Control System ◽  
Fuel Injection ◽  
Time History ◽  
Pressure Control ◽  
Rail Pressure ◽  
High Pressure Pump ◽  
Pressure Time ◽  
Pressure Control System ◽  
Injection Apparatus

A fully predictive model of a Common Rail fuel injection apparatus, which includes a detailed simulation of rail, pump, piping system, injectors and rail pressure control system, is presented and discussed. The high-pressure pump and injector sub-models have been validated separately and then coupled to the rail and pressure control system sub-models. The complete predictive model has been validated and applied to investigate the effects of the dynamics of each component of the injection apparatus on the rail pressure time history. Variable timing of the high-pressure pump delivery phases has also been considered, and the influence of this parameter on the injection performance has been analysed for both single- and multiple-injection events. Furthermore, the injection system dynamics during the transients between steady-state working conditions has been investigated in order to highlight the role played by the dynamic response of the pressure control system on the rail pressure time history.

Petroleum Well Blowouts as a Threat to Drilling Operation and Wellbore Sustainability: Causes, Prevention, Safety and Emergency Response

2021 ◽  
Author(s):  
Hamzeh Ghorbani ◽  
◽  
Mohammad Reza Abdali ◽  
Nima Mohamadian ◽  
David A. Wood ◽  
...  
Keyword(s):  
Emergency Response ◽  
Surface Damage ◽  
Lessons Learned ◽  
Fire Control ◽  
Safety Measures ◽  
Well Control ◽  
Drilling Operation ◽  
Drilling Rig ◽  
Petroleum Wells ◽  
Safety Systems

Sustainability in petroleum wells drilling operation systems strongly depends on the use of sustainable materials and a set of technical and safety measures that lead to the survival and proper operation of drilling rig equipment's and personnel. Adherence to the highest levels of standards of tools, materials and methods, although always recommended as the most important option for advancing a safe drilling operation and completing the well efficiently, low risk and stable, but drilling operation is inherently a battle with underground challenges and unexpected dangers. Learning from past such well blowout events and the problems they pose to rapidly control is essential to reduce future impacts including injuries, damage and emissions. Such analysis offers guidance for adapting working practices to improve both prevention and emergency response to such incidents. The causes of blowout during drilling and the necessary technical and safety measures to adopt are reviewed, highlighting how best practices can prevent blowout incidents by improving responses to early warning signals. The particular risks associated with potential shallow gas blowouts are identified and described with the aid of a case study associated with a catastrophic blowout of an onshore well in Iran and the methods used to ultimately control it. The multiple causes of the incident relating to defects in safety systems, equipment and operating procedures are addressed. Lessons learned from the incident reveal the complexity of well control once a blowout incident has occurred and developed into a surface fire. from the stage of the incident to fire control. There is a need for further research into top-hole well kill techniques for wells in a blowout state, as drilling bottom-hole relief wells takes substantial time, during which much surface damage, resource loss and emission typically occurs.

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