Coiled Tubing Dewaxing Operations: Case Studies in Reduced Production Wells of Northeast India

2021 ◽  
Author(s):  
Ishaan Singh ◽  
Akash Ramesh Pathak ◽  
Juhi Kaushik ◽  
Bholanath Bandyopadhyay ◽  
Danny Aryo Wijoseno ◽  
...  

Abstract Executing interventions in wells encrusted with wax is challenging because experience with global coiled tubing (CT) dewaxing operations is limited, and equipment failure and stuck pipe risks are high. With few jobs performed worldwide, CT dewaxing (hot oil circulation with CT) operations are largely unexplored. The deviated wells in a field in northeast India pose several challenges including completely seized wellbore due to paraffin/asphaltene deposition, previous failed well cleanout attempts, very slow and low bottomhole assembly (BHA) penetration, pumping corrosive and flammable low wax crude (LWC) through CT, high chances of CT getting stuck, and pumping heated 69°C LWC through the CT. This case study delivers insights about design, safety, and operational considerations for 1.5-in. CT dewaxing and nitrogen lift operations in a subhydrostatic well in the field. The objective of this CT dewaxing and nitrogen kickoff operation was to clear the well of paraffin/asphaltene/wax to 1600 m and activate it with nitrogen, and this paper describes solutions for cleaning out and nitrogen-lifting wells with declining production due to paraffin and asphaltene deposition. One well is described in this case study, but this approach can be used perform CT intervention in similar wells. For this case, simulations were sensitized to identify the best combination of pumping rates, CT speeds, and fluid temperature to remove deposits hindering BHA penetration. This study proposes prevention measures using appropriate grounding and procedures, which determine if the crude oil can be pumped through CT. By use of this methodology, 581 dewaxing runs have been performed in 78 wells. Extensive on-job experience and lessons learnt by performing this operation over the last 3 years bring excellent results and prevent misruns. In many cases, production has been restored from nil; several examples feature a fivefold improvement of productivity thanks to this intervention method. Optimized operational parameters such as CT speed, pumping rates, and the use of smaller outer diameter BHAs doubled operational efficiency during those operations. In addition, strict application of the recommendations prevented the occurrence of operational problems such as stuck CT, crude oil flashing, sand bridging, and equipment failure.

2021 ◽  
Vol 2129 (1) ◽  
pp. 012013
Author(s):  
Kung Yee Han ◽  
Akhmal Sidek ◽  
Aizuddin Supee ◽  
Radzuan Junin ◽  
Zaidi Jaafar ◽  
...  

Abstract This paper seeks to determine the optimum operating conditions for deploying casing perforation guns based on CT to target depths in gas well MA-X by utilising Orpheus Model in CERBERUS. Orpheus assisted to solve the complicated scenarios and complex analysis involves mathematical modelling which is necessitates for computer processing powers. This study investigated four different Coiled Tubing (CT) intervention operational variables namely borehole assembly, CT grade outer diameter (OD), well fluid type and fractional reducer application included examined two scenarios which are running tools in (RIH) and pulling out from borehole (POOH). Only CT workstring with outer diameter between 1-1/4 inch and 2-7/8 inch is considered due to the wellbore completion minimum restriction. Constrained by economic and logistical reasons, only fresh water, 2% KCl, 15% HCl, sea water and diesel will be considered for the well bore fluid. Fractional reducer effects was simulated and analysed. Based on simulation results, the CT outer diameter 1-3/4 inch workstring optimized operation, the CT grade is QT1000 increased mechanical properties. A suitable well fluid is sea water with application of friction reducer improve CT perforation performances to achieve maximum target depth.


Author(s):  
Konstantinos Gkillas ◽  
Christoforos Konstantatos ◽  
Athanasios Tsagkanos ◽  
Dimitrios I. Vortelinos

2021 ◽  
Vol 23 (4) ◽  
pp. 1847-1860
Author(s):  
Christopher S. McCallum ◽  
Wanling Wang ◽  
W. John Doran ◽  
W. Graham Forsythe ◽  
Mark D. Garrett ◽  
...  

A life cycle thinking analysis (LCT) conducted on the production of vanillin via bamboo wet air oxidation compared to vanillin production from crude oil or kraft lignin.


2012 ◽  
Author(s):  
Riyaz Kharrat ◽  
Zeynab Zargar ◽  
Seyed Mahdi Razavi

Author(s):  
Kajum Safiullin ◽  
Vyacheslav Kuzmin ◽  
Alexander Bogaychuk ◽  
Egor Alakshin ◽  
Lisset Miquel González ◽  
...  
Keyword(s):  

2021 ◽  
Author(s):  
Sufyan Deshmukh ◽  
Marcelo Dourado Motta ◽  
Sameer Prabhudesai ◽  
Mehul Patil ◽  
Yogesh Kumar ◽  
...  

Abstract A unique invert emulsion fluid (IEF) weighted up with treated micronized weighting agent (MWA) slurries has been developed and successfully implemented in the field as a completion and testing fluid. The utilization of this unique IEF by design allowed the fluid properties to be lower on viscosity and superior suspension characteristics, which allowed for thermally stable fluid and provided excellent downhole hydraulics performance. Much of the earlier development and deployment of this type of IEF was focused on drilling for sections in narrow mud weight and fracture gradient windows, coiled tubing operations, managed pressure drilling, and extended reach wells. Many of these drilling challenges are also encountered in high pressure and high temperature (HTHP) and ultra-deepwater field developments and mature, depleted fields. Early fluid developments focused on designing the fluids chemistry and physics interactions and the optimization of mineralogy of the weighing agent used. There was also some concern on variability of the results seen on the return permeability as well as standard fluid loss experiments. The paper describes the laboratory and field and rigsite data generated while using the MWA in IEFs during completion operations with a client in India. The paper will briefly describe the laboratory work before the application and the associated results observed on the rig site. It will also outline all the challenges which were faced during the execution and mixing of the MWA IEFs. Each separate operation required a high-density reservoir fluid solution above 15.5 ppg [1.85 sg]. Because corrosion, sag potential, and scale were the operator's main concerns, a solids-free brine or other type of weighting agent (for e.g. Calcium Carbonate and/or Tri-Manganese Tetra Oxide) solution was not favored. A high-density IEF designed with MWA allowed us to provide a solution that mitigated against the risks identified in each operation. The thin viscosity profile enabled completion activities to proceed with minimal fluid consumption at surface, reducing the overall environmental impact. The high-density (15.6 ppg [1.86 SG] and 16.2 ppg [1.94 SG]) invert emulsion fluid was designed to minimize sag potential with minimal reservoir damage potential. With a thinner viscosity profile compared to conventional IEFs at equivalent densities, the fluid enabled completion activities with minimal fluid volumes lost over shakers and reduced the environmental impact. The MWA that was used to build the IEF used for drilling and completion fluid enabled maintenance of extremely low-shear rate viscosities when compared to conventional barite-laden fluids. This fluid was used for suspending and abandoning the well in Case Study A, where the reentry and intervention of the well was planned to be after 2 years. After exposure of the fluid in Case Study A, the fluid showed minimum sag after re-entry of the well and the intervention activities were done without any problems. Case Study B showed that the fluid was mixed to the density of 16.2 ppg and was used to perforate and test two different zones. The bottom hole static temperature (BHST) reported were 356 degF (180 degC) for Case Study A and 376 degF (191 degC) for Case Study B respectively. The paper attempts to show the effects of using this alternative weighing agent as a completion fluid instead of a high-density solids-free brine or other solids-laden high-density brines and the associated success, which could be managed if the fluid design is carefully planned.


2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Jaswar Koto ◽  
Abd. Khair Junaidi ◽  
M. H. Hashim

Offshore pipeline is mainly to transport crude oil and gas from offshore to onshore. It is also used to transport crude oil and gas from well to offshore platform and from platform to another platform. The crude oil and gas horizontally flows on the seabed, and then vertically flows inside the riser to the offshore platform. One of current issues of the oil and gas transportation system is an end expansion caused by the axial force. If the end expansion occurs over it limit can cause overstress to riser. This paper explores the effect of axial force toward local buckling in end expansion. In the study, development of programming in visual basic 2010 firstly was constructed using empirical equation. The programming code, then, was validated by comparing simulation result with actual data from company. As case study, the end expansion for various thicknesses of pipes was simulated. In this programming, DNV regulation is included for checking either design complied or not with regulation. However, DNV regulation doesn’t have specific rule regarding the end expansion but it is evaluated under load displacement control under strain condition.


Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 417 ◽  
Author(s):  
Vahid Radmehr ◽  
Sied Shafaei ◽  
Mohammad Noaparast ◽  
Hadi Abdollahi

Recovery is one of the most important metallurgical parameters in designing and evaluating flotation circuits. The present study used the recovery arrangement for two and three stage circuits to evaluate the effect of stage recovery on the overall circuit recovery and flotation circuit configuration. The results showed that mainly the highest recovery value should be assigned to the rougher stage in order to achieve the maximum overall circuit recovery. Countercurrent rougher-cleaner and rougher-scavenger circuits, in which recycling streams step back one stage at a time, follow a general rule for the assignment of recovery. Finally, a flotation plant containing six flotation banks was examined as a case study. A program for calculating total circuit recovery, for all possible combinations of recovery was developed in MATLAB software. 720 recovery combinations were evaluated. The results showed that optimal recovery allocation in stages could be effective in achieving overall circuit recovery. It was shown that the use of a large number of stages in some of the flotation circuits leads to the loss of equipment and additional costs. The proposed approach can be employed as an effective tool for designing and optimizing various flotation circuits and their operational parameters.


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