A Spectacular Cementing Record in Myanmar Offshore Deepwater Well

2021 ◽  
Author(s):  
Gang Sun ◽  
Mohammad Solim Ullah ◽  
Yi Li ◽  
Mukesh Maheshwari ◽  
Thirayu Khumtong ◽  
...  

Abstract Myanmar offshore is considered to be a very promising exploration and production (E&P) location for oil and gas but poses significant challenges to drilling and cementing operations. Low temperature at sea bed delays the cement compressive strength development, High pore pressure with steep gradient and low fracture pressure created a very narrow drilling margin, presence of shallow flow in riser-less section further complicated the cementing operation, low density cement with high performance is a must. With the exorbiant cost of Deepwater drilling, much needed fit for purpose cementing technology with efficient logistic support and excellence in execution became crucial. This paper elaborates the cementing challenges at different sections of a recent deep-water well in offshore Mynamar and techniques that were planned and used to address those challenges. This paper will describe in detail the cementing method, how it fit the well situation, how the cement slurry was designed then evaluated and how the logistic support and execution were carried out, resulting in a resounding success.

2014 ◽  
Vol 34 (5) ◽  
pp. 405-413
Author(s):  
Xianru He ◽  
Qian Chen ◽  
Chunhui Feng ◽  
Liang Wang ◽  
Hailong Hou

Abstract High performance cement slurry polymer modifiers are increasingly in demand in the cementing process of oil and gas. A new polymer modifier with outstanding fluid loss control and high strength and toughness was synthesized by the main monomers butyl acrylate (BA), methyl methacrylate (MMA), acrylamide (AM), the functional monomers vinyltriethoxysilane (VTS), glycidyl methacrylate (GMA) and the initiator of ammonium persulfate (APS) through emulsion polymerization. By using Fourier transform infrared (FTIR) spectrometer, a laser particle analyzer, a scanning electron microscope and a differential scanning calorimeter, we studied the mechanism of fluid loss control and microstructure of polymer latex cement slurries. The experimental results showed that the copolymer could be crosslinked at 160°C and have the lowest fluid loss control, 12 ml, when the polymer content reached 5%. Acrylate latex modified by the silane coupling agent VTS had excellent performance on fluid loss control, as well as mechanical properties for oil well cement. These results have a potential significant value for the development of a new polymer cement modifier with high thermal stability and durability.


2014 ◽  
Vol 600 ◽  
pp. 485-494
Author(s):  
Ahcene Merida ◽  
Fattoum Kharchi ◽  
Rabah Chaid

In Algeria, locally available natural pozzolan of volcanic origin material has the potential for use in environmental friendly concrete as a partial cement replacement. This paper studies the effect of replacement level of pozzolan concrete in sulphated environment. The natural pozzolan has a marked influence on the properties of the concrete. When it is coupled to a water reducing superplasticizer by a correct adjustment of the composition, it greatly improves the concrete properties. The analysis of experimental results on pozzolan concrete at 5% content and fineness of 9565 cm2/g exposed in sulphated environment, show that it positively contributes to the improvement of its mechanical, physical and physico-chemical characteristics. Trough this research work, parameters such as compressive strength development, chloride permeability, water absorption and sulphates resistance are studied.


2020 ◽  
Vol 10 (20) ◽  
pp. 7107
Author(s):  
Pham Sy Dong ◽  
Nguyen Van Tuan ◽  
Le Trung Thanh ◽  
Nguyen Cong Thang ◽  
Viet Hung Cu ◽  
...  

This research investigated the effect of fly ash content on the compressive strength development of ultra-high-performance concrete (UHPC) at different curing conditions, i.e., the standard curing condition and the heat curing. A total of 20 mixtures were prepared to cast specimens to measure the compressive strength at different ages from 3 days to 180 days. Additionally, 300 specimens were prepared to estimate the appropriate heat curing period at the early ages in terms of enhancing the 28-day compressive strength of UHPC with high content of fly ash (FA). From the regression analysis using test data, empirical equations were formulated to assess the compressive strength development of UHPC considering the FA content and maturity function. Test results revealed that the preference of the addition of FA for enhancing the compressive strength of UHPC requires the early heat curing procedure which can be recommended as at least 2 days under 90 °C. Moreover, the compressive strength of UHPC with FA under heat curing mostly reached its 28-day strength within 3 days. The proposed models based on the fib 2010 model can be a useful tool to reliably assess the compressive strength development of UHPC with high-volume fly ash (HVFA) (up to 70% fly ash content) under a heat curing condition that possesses a different performance from that of normal- and high-strength concrete. When 50% of the cement content was replaced by FA, the embodied CO2 emission for UHPC mixture reduced up to approximately 50%, which is comparable to the CO2 emission calculated from the conventional normal-strength concrete.


2021 ◽  
Author(s):  
Maxim Viktorovich Miklyaev ◽  
Ivan Vyacheslavovich Denisov ◽  
Ivan Mikhailovich Gavrilin

Abstract Well construction in the Volga-Ural Region faces different sorts of complications, the most common ones being the loss of drilling fluids and rockslides. Such complications may cause considerable financial losses due to non-productive time (NPT) and longer well construction periods. Moreover, there are complications, which might occur both during well construction and during its exploitation. The commonest complications are sustained casing pressure (SCP) and annular flow. The complications, which occur when operating a well, also have a negative effect on the economic efficiency of well operation and call for additional actions, for example, repair and insulation works, which require well shutdown and killing, though a desired outcome still cannot be guaranteed; moreover, it is possible that several different operations may have to be carried out. In addition, the occurrence of SCP during well life is one of the most crucial problems that may cause well abandonment due to high risks posed by its operation. It is known that the main reasons for SCP are as follows: Channels in cement stone Casing leaks Leaks in wellhead connections To resolve the problem of cement stone channeling, several measures were taken, such as revising cement slurry designs, cutting time for setting strings on slips, applying two-stage cementing, etc. These measures were not successful, besides, they caused additional expenses for extra equipment (for example, a cementer). In order to reduce the risk of cement stone channeling, a cementing method is required that will allow to apply excess pressure on cement slurry during the period of transition and early strength development. To achieve this goal, a well-known method of controlled pressure cementing may be applied. Its main drawback, however, is that it requires much extra equipment, thus increasing operation expenses. In addition, the abovementioned method allows affecting the cement stone only during the operation process and / or during the waiting on cement (WOC) time. Upon receiving the results of the implemented measures and considering the existing technologies and evaluating the economic efficiency, the need was flagged for developing a combined cementing method. The goal of this method is to modify the production string cementing method with a view to applying excess pressure on cement stone during strength development and throughout the well lifecycle. The introduction of this lining method does not lead to an increase in well construction costs and considerably reduces the risks of losing a well from the production well stock.


2021 ◽  
Author(s):  
Thein Zaw Phyoe ◽  
Jose Salazar ◽  
Eduardo Herrera Albuja ◽  
Saurabh Kapoor ◽  
Mohd Waheed Orfali ◽  
...  

Abstract Lost circulation while drilling across vugular or naturally fractured formations is a difficult challenge which will come with high cost for the oil and gas industry. When lost circulation encounter, the drilling company will result in nonproductive time and remedial operational expenses. Most of the fields in UAE are encountering lost circulation problems while drilling across surface sections, which are difficult to control with conventional lost circulation solutions. Newly engineered high-performance lightweight thixotropic proves beneficial to control losses in vugular and natural fractured formations. The main challenge while drilling the surface section in one UAE field is the total loss of returns and flowing formation. This leads to the inability to continue drilling due logistics to continue producing drilling fluid and to keep the well under control and risk of stuck pipe due to poor cuttings removal. Conventional low-density cement slurries have been widely used to cure losses while drilling, but with low effectiveness. A new lost circulation solution that combines lightweight (10.5–lbm/galUS) high-performance cement and a thixotropic agent produce an engineered high-performance lightweight thixotropic lost circulation solution with fast gel strength and improved compressive strength, enabling the plugging of large voids and fractures to recovery wellbore integrity required to continue drilling. Extensive laboratory qualification tests were performed for static gel strength development to confirm the plugging efficiency and compressive strength development. The results were promising with more than 110 lbf/100 ft2 of static gel strength in 10 minutes and compressive strength development of 1,000 psi within 24 hours at low surface temperature. In addition, a transition time (TT) with on-off-on test demonstrated more faster gel strength development was developed when the reduction of the shear rate and regained pumpable with reapplication of shear. In one of the wells, total losses were encountered while drilling across surface section. The lightweight high-performance thixotropic solution was pumped for the first time worldwide, proved that the innovative lost circulation solution was effective in curing the losses, and enabled the operator to continue drilling the section to TD. This case study demonstrates that the engineered system is effective in curing losses and reducing nonproductive time. The unique properties of more faster gel strength and enhanced compressive strength make this system more effective for treating a different types of lost circulation scenarios during drilling (Jadhav and Patil, 2018). New high-performance lightweight thixotropic cement lost circulation solution exhibits strong performance in curing total losses and establishing well integrity with reliability.


Author(s):  
Raymos Kimanzi ◽  
Harshkumar Patel ◽  
Mahmoud Khalifeh ◽  
Saeed Salehi ◽  
Catalin Teodoriu

Abstract Cement plugs are designed to protect the integrity of oil and gas wells by mitigating movement of formation fluids and leaks. A failure of the cement sheath can result in the loss of zonal isolation, which can lead to sustained casing pressure. In this study, nanosynthetic graphite with designed expansive properties has been introduced to fresh cement slurry. The expansive properties of nanosynthetic graphite were achieved by controlling the preparation conditions. The material was made from synthetic graphite and has a surface area ranging from 325–375 m2/gram. Several tests including compressive strength, rheology, and thickening time were performed. An addition of 1% nanosynthetic graphite with appropriate reactivity was sufficient to maintain expansion in the cement system, leading to an early compressive strength development. It has excellent thermal and electrical conductivity and can be used to design a cement system with short and long-term integrity. Rheology and thickening time tests confirmed its pumpability. Controlling the concentration of the additive is a promising method that can be used to mitigate gas migration in gas bearing and shallow gas formations.


2021 ◽  
Vol 15 (1) ◽  
pp. 59-65
Author(s):  
Maryna Petruniak ◽  
Victoriia Rubel ◽  
Vira Chevhanova ◽  
Svitlana Kulakova

Purpose. Research and substantiating the expediency of cement mix formulations of grout slurries with different Defecate additive content and their effective use when cementing the reservoirs prone to absorption of the cement slurry, as well as to prevent behind-the-casing flows and for cementing operations in the zone of abnormal pressures (hydraulic seam fracturing). Methods. Analytical and experimental studies of the physical-chemical grout slurry properties are used: determining the influence of the Defecate additive content on the cement mixture technological properties; study of a change in the grout slurry rheological characteristics at various temperature conditions; testing the formulation of grout slurry with different rates of strength development; substantiating the economic efficiency of using the grout mixtures with the Defecate additive. Findings. It has been revealed that the cement mixture fluidity increases by 10-20% with the addition of a Defecate in the proportion of 5-20%. With a further increase in the Defecate content, the stone strength deteriorates, and with a decrease, the grout slurry concentration increases. It has been found that when Defecate is added to the cement mixture in a proportion of 20%, the pumpability of the cement slurry doubles, that is, from 1.5 to 3 hours. The economic efficiency has been proved of using these mixtures during insulating activities in the well No. 122 of the Kulychykhynske NHKR (oil and gas condensate field). The improved formulations of grout slurry with the addition of a Defecate are recommended to be used during repair-insulation works for delimitation of producing reservoirs prone to absorption, behind-the-casing flows and hydraulic fracturing. Originality.New dependences have been determined of the technological and rheological characteristics of grout slurries on the content of the Defecate additive, which makes it possible to set its optimal proportion. Practical implications. The use of grout mixture based on the Defecate will expand the raw material base for obtaining lightweight grout slurries. The properties of such a solution make it possible to use a grout mixture for cementing wells in the zone of abnormal pressures, while reducing the costs for the process of reservoir delimitation. Keywords: well, behind-the-casing flows, producing reservoir, grout slurry, Defecate


2012 ◽  
Vol 476-478 ◽  
pp. 1688-1691 ◽  
Author(s):  
Xue Song Zhang

Based on the mechanism of concrete carbonation, the effects of content of fly ash in the binder, the water to binder ratios, compound activator, and long-term curing on the carbonation depth of fly ash high-performance concrete are investigated. Experiment results are analyzed and compared with compressive strength development characteristic of fly ash high-performance concrete, and some valuable conclusions are gained.


2013 ◽  
Vol 53 (6) ◽  
pp. 901-905 ◽  
Author(s):  
Radoslav Sovják ◽  
Filip Vogel ◽  
Birgit Beckmann

The aim of this work is to describe the strength of Ultra High Performance Concrete (UHPC) under triaxial compression. The main goal is to find a trend in the triaxial compressive strength development under various values of confinement pressure. The importance of triaxial tests lies in the spatial loading of the sample, which simulates the real loading of the material in the structure better than conventional uniaxial strength tests. In addition, the authors describe a formulation process for UHPC that has been developed without using heat treatment, pressure or a special mixer. Only ordinary materials available commercially in the Czech Republic were utilized throughout the material design process.


Sign in / Sign up

Export Citation Format

Share Document