Cementing Solutions for Monobore Challenges

2021 ◽  
Author(s):  
Thien Yu Loh ◽  
Anh Tuan Duong ◽  
Woon Phin Chong
Keyword(s):  
Evaluation Process ◽  
Well Design ◽  
Pressure Test ◽  
Cement System ◽  
Open Hole ◽  
Zonal Isolation ◽  
Single Production ◽  
Mechanical Separation ◽  
Production Tubing ◽  
Successful Production

Abstract Monobore cementation is defined as where a single production tubing size runs from the pay zone all the way to surface and is cemented in place. This type of well design greatly reduce rig time and cost. The challenge however is to achieve a good cement in the annulus as a well barrier and to have a clean internal tubing after the cementing job to allow for successful production of the well. To achieve a clean internal tubing, a distinct bottom and top plugs were used as a means of mechanical separation. For fluids design, mud had to be thinned down prior to the cementing job and, a designed fiber based spacer system was used to physically scrub any mud-film sticking on the tubing walls. The centralizers and cement system were designed to allow for efficient displacement of mud and hence providing good overall placement and top of cement in the tubing-casing annulus. The cement in the annulus will be verified by pressure testing the annulus to 500 psi higher than previous shoe leak-off. This approach was implemented for the campaign of six wells, all designed with 5-1/2in monobore tubing. The bottomhole static temperature (BHST) of the well ranges from 300 to 350°F. The cementing system also had to be designed to cater to the challenge of this field, having CO2 as high as 60%, high temperatures, and a long open hole section that requires isolation and cement to set within a required timeframe. The cementing jobs were validated by no losses or gains during the job, floats holding at the end of the cementing job, differential pressure of cement prior to bumping the plug, density and pump rates executed as planned, accepted pressure test criteria of the annulus, output validation of cement contamination in pipe and annulus based on fluids and final well information. To further validate this system, the cement bond log was also run as part of the evaluation process and the cement log showed that zonal isolation was achieved. After the perforations, the perforation tool was pulled out to surface and the tool looked very clean with no signs of contaminated mud or cement around the tool. We demonstrate how this unique cementing approach can be a solution for the challenges of monobore cementing and one of the biggest problems of monobore cementing in the industry.

Assurance of Long-Term Well Integrity in Highly Corrosive Downhole Environment

2021 ◽  
Author(s):  
Mohammad Arif Khattak ◽  
Agung Arya Afrianto ◽  
Bipin Jain ◽  
Sami Rashdi ◽  
Wahshi Khalifa ◽  
...  
Keyword(s):  
Gas Production ◽  
Simulation Software ◽  
Successful Implementation ◽  
Horizontal Section ◽  
Well Integrity ◽  
Well Design ◽  
Cement System ◽  
Zonal Isolation ◽  
Fit For Purpose

Abstract Portland cement is the most common cement used in oil and gas wells. However, when exposed to acid gases such as carbon dioxide (CO2) and hydrogen sulfide (H2S) under downhole wet conditions, it tends to degrade over a period of time. This paper describes the use of a proprietary novel CO2 and H2S resistant cement system to prevent degradation and provide assurance of long-term wellbore integrity. The CO2-resistant cement was selected for use in one of the fields in Sultanate of Oman after a well reported over 7% CO2 gas production resulting in well integrity failure using conventional cements. The challenge intensified when the well design was modified by combining last two sections into one long horizontal section extending up to 1,600 m. The new proposed cement system was successfully laboratory- tested in a vigorous CO2 environment for an extended period under bottomhole conditions. Besides selecting the appropriate chemistry, proper placement supported by advanced cement job simulation software is critical for achieving long-term zonal isolation. The well design called for a slim hole with 1,600 m of 4 ½-in liner in a 6-in horizontal section where equivalent circulating density (ECD) management was a major challenge. An advanced simulation software was used to optimize volumes, rheologies, pumping rates, and ECDs to achieve the desired top of cement. The study also considered a detailed torque and drag analysis in the horizontal section, and fit- for-purpose rotating-type centralizers were used to help achieve proper cement coverage. To date, this cement system has been pumped in 32 wells, including 24 with 6-in slimhole horizontal sections with no reported failures. The paper emphasizes the qualification and successful implementation of fit-for-purpose design of CO2- and H2S-resistant cement as well as optimized execution and placement procedures to achieve long-term zonal isolation and well integrity in a complex slimhole horizontal well design.

Successful Remediation of Sustained Casing Pressures in Gas Cap Injector Wells with the Use of Flexible and Self Healing System

2021 ◽  
Author(s):  
Bipin Jain ◽  
Abhijeet Tambe ◽  
Dylan Waugh ◽  
Moises MunozRivera ◽  
Rianne Campbell
Keyword(s):  
Self Healing ◽  
Injection Wells ◽  
Coiled Tubing ◽  
Cement System ◽  
Sustained Casing Pressure ◽  
Casing Pressure ◽  
New Generation ◽  
Prudhoe Bay ◽  
Production Tubing

Abstract Several injection wells in Prudhoe Bay, Alaska exhibit sustained casing pressure (SCP) between the production tubing and the inner casing. The diagnostics on these wells have shown communication due to issues with casing leaks. Conventional cement systems have historically been used in coiled-tubing-delivered squeeze jobs to repair the leaks. However, even when these squeeze jobs are executed successfully, there is no guarantee in the short or long term that the annular communication is repaired. Many of these injector wells develop SCP in the range of 300-400 psi post-repair. It has been observed that the SCP development can reoccur immediately after annulus communication repair, or months to years after an injector well is put back on injection. Once SCP is developed the well cannot be operated further. A new generation of cement system was used to overcome the remedial challenge presented in these injector wells. This document provides the successful application of a specialized adaptive cement system conveyed to the problematic zone with the advantage of using coiled tubing equipment for optimum delivery of the remedial treatment.

Successful Single-Stage Cementing in a Weak Formation: A Case History in Spain

2014 ◽  
Author(s):  
A.. Bottiglieri ◽  
A.. Brandl ◽  
R.S.. S. Martin ◽  
R.. Nieto Prieto
Keyword(s):  
Engineering Design ◽  
Case History ◽  
Laboratory Testing ◽  
Single Stage ◽  
Formation Damage ◽  
Cement Slurry ◽  
Integrity Test ◽  
Open Hole ◽  
Zonal Isolation ◽  
Horizontal Wellbore

Abstract Cementing in wellbores with low fracture gradients can be challenging due to the risk of formation breakdowns when exceeding maximum allowable equivalent circulation densities (ECDs). Consequences include severe losses and formation damage, and insufficient placement of the cement slurry that necessitates time-consuming and costly remedial cementing to ensure zonal isolation. In recent cementing operations in Spain, the formation integrity test (FIT) of the open hole section indicated that the formation would have been broken down and losses occurred based on calculated equivalent circulating densities (ECDs) if the cement slurry had been pumped in a single-stage to achieve the operator's top-of-cement goal. As a solution to this problem, cementing was performed in stages, using specialty tools. However, during these operations, the stage tool did not work properly, wasting rig time and resulting in unsuccessful cement placement. To overcome this issue, the operator decided to cement the section in a single stage, preceded by a novel aqueous spacer system that aids in strengthening weak formations and controlling circulation losses. Before the operation, laboratory testing was conducted to ensure the spacer system's performance in weak, porous formations and better understand its mechanism. This paper will outline the laboratory testing, modeling and engineering design that preceded this successful single stage cementing job in a horizontal wellbore, with a final ECD calculated to be 0.12 g/cm3 (1.00 lb/gal) higher than the FIT-estimated figure.

Triple MPD Technique for Drilling and Intelligent Completion Deployment on an Abandoned Deepwater Well

2021 ◽  
Author(s):  
André Alonso Fernandes ◽  
Eduardo Schnitzler ◽  
Fabio Fabri ◽  
Leandro Grabarski ◽  
Marcos Vinicius Barreto Malfitani ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Fluid Loss ◽  
Final Project ◽  
Well Design ◽  
Open Hole ◽  
Loss Control ◽  
Fluid Losses ◽  
Complex Cases ◽  
Total Fluid

Abstract This is a case study of a presalt well that required the use of 3 different MPD techniques to achieve its goals. The well was temporary abandoned when conventional techniques failed to reach the final depth. Total fluid losses in the reservoir section required changing the well design and its completion architecture. The new open hole intelligent completion design had to be used to deliver the selective completion in this challenging scenario. From the hundreds of wells drilled in the Santos basin presalt, there are some wells with tight or no operational drilling window. In order to drill these wells different MPD techniques are used. In most cases, the use of Surface Backpressure (SBP) technique is suitable for drilling the wells to its final depth. For the more complex cases, when higher fluid loss rates occur, the use of SBP and Pressurized Mud Cap Drilling (PMCD) enables the achievement of the drilling and completion objectives. After the temporary abandonment of this specific well in 2018, the uncertainty of the pore pressure could not ensure that the SBP and PMCD techniques would be applicable when reentering the well. To avoid difficult loss control operations, the completion team changed the intelligent completion design to include a separated lower completion, enabling its installation with the MPD system. Besides the previously used MPD techniques, the integrated final project considered an additional technique, Floating Mud Cap Drilling (FMCD), as one of the possible contingencies for the drilling and completion phases. Well reentry and drilling of the remaining reservoir section included the use all the previously mentioned MPD techniques (SBP, PMCD and FMCD). The lower completion deployment utilized the FMCD technique to isolate the formation quickly and efficiently, without damaging the reservoir. The planning and execution of the well faced additional difficulties due to the worldwide pandemic and personnel restrictions. The success from the operation was complete with no safety related events and within the planned budget. At the end, the execution team delivered a highly productive well with an intelligent completion system fully functional, through an integrated and comprehensive approach. MPD use on deepwater wells is relatively new. Different operators used several approaches and MPD techniques to ensure safety and success during wells constructions over the last decade. This paper demonstrates the evolution of MPD techniques usage on deepwater wells.

Nanosized Magnesium Oxide With Engineered Expansive Property for Enhanced Cement-System Performance

SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1681-1689 ◽  
Author(s):  
Narjes Jafariesfad ◽  
Mette Rica Geiker ◽  
Pål Skalle
Keyword(s):  
Heat Treatment ◽  
Young’S Modulus ◽  
Magnesium Oxide ◽  
Young's Modulus ◽  
Oil Well ◽  
Cement Slurry ◽  
Expansive Agent ◽  
Cement System ◽  
Zonal Isolation

Summary The bulk shrinkage of cement sheaths in oil wells can result in loss of long-term zonal isolation. Expansive additives are used to mitigate bulk shrinkage. To compensate effectively for bulk shrinkage during the late plastic phase and the hardening phase of the cement system, the performance of the expansive additive needs to be regulated considering the actual cement system and placement conditions. This paper presents an introductory investigation on the potential engineering of nanosized magnesium oxide (MgO) (NM) through heat treatment for use as an expansive agent in oilwell-cement systems. In this study, the bulk shrinkage of a cement system was mitigated by introducing NM with designed reactivity to the fresh cement slurry. The reactivity of NM was controlled by heat treatment. A dilatometer with corrugated molds was used to measure the linear strain of samples cured at 40°C and atmospheric pressure. The effect of NMs differing in reactivity on tensile properties of cement systems cured for 3 days at 40°C was examined by use of the flattened Brazilian test. The reactivity of the NM played a key role in controlling the bulk shrinkage of the cement system. Addition of only 2% NM by weight of cement (BWOC) with appropriate reactivity was sufficient to maintain expansion of the cement system. Adding NM to the cement system also resulted in improved mechanical flexibility. The NM with highest reactivity caused the largest reduction in Young's modulus at 3 days and, in general, the ratio of tensile strength to Young's modulus improved through the addition of NM to the cement system. Our work demonstrates that controlling the reactivity of the additive is a promising method to mitigate bulk shrinkage of cement systems and thereby to sustain the mechanical properties of the cement sheath in the oil well at an acceptable level.

Improved Zonal Isolation in Open Hole Applications

2014 ◽  
Author(s):  
Johnny Bardsen ◽  
Paul Hazel ◽  
Ricardo R. Reves Vasques ◽  
Oyvind Hjorteland ◽  
Oystein Eikeskog
Keyword(s):  
Open Hole ◽  
Zonal Isolation

Flexible, Expanding Cement System (FECS) Successfully Provides Zonal Isolation Across Marcellus Shale Gas Trends

2011 ◽  
Author(s):  
Robert Heath Williams ◽  
Deepak Kumar Khatri ◽  
Roger F. Keese ◽  
Sylvaine Le Roy-Delage ◽  
Justin Martin Roye ◽  
...  
Keyword(s):  
Shale Gas ◽  
Marcellus Shale ◽  
Cement System ◽  
Zonal Isolation

scholarly journals Efficiency improvement of technical condition assessment of plunger pairs of diesel fuel equipment

2020 ◽  
Vol 329 ◽  
pp. 01018
Author(s):  
Anatolii Eremeev ◽  
Aleksandr Morozov ◽  
Dmitry Kotkov
Keyword(s):  
Diesel Fuel ◽  
Evaluation Process ◽  
Condition Assessment ◽  
Technical Condition ◽  
Test Time ◽  
Hydraulic Pressure ◽  
Efficiency Improvement ◽  
Pressure Test ◽  
Time Record

Usage of an upgraded device for assessing technical condition of plunger pairs makes it possible to increase assessment accuracy and reduce the number of erroneously rejected plunger pairs. The action of this device is based on introduction of automatic hydraulic pressure test time record into the evaluation process.

Sign in / Sign up

Export Citation Format

Share Document