Challenging Horizontal Well Abandoned with Innovative Plug Setting Technique and Tailored Slurry Design

2021 ◽  
Author(s):  
Dinesh Simmadorai ◽  
M Syafiq M Ariffin ◽  
Mayank Patil ◽  
David Franke ◽  
Aizat Noh ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Negative Impact ◽  
Cement Slurry ◽  
Horizontal Section ◽  
Support Tool ◽  
Main Challenge ◽  
Open Hole ◽  
Bottom Hole Assembly ◽  
Drilling Operations ◽  
Cement Plug

Abstract Setting multiple plugs across a horizontal well can be a challenge. One way to do this is using the "pump and pull" methodology to achieve the objectives set out by the project team. Tailoring of the cement slurries and the execution of cementing operations for the successful deployment of multiple cement plugs using this method to achieve a dependable barrier across a horizontal reservoir section will be reviewed and discussed. A development well in Malaysia lost a bottom hole assembly (BHA) in their 8.5" hole section. This resulted in the requirement to abandon a long horizontal section along with the requirement to spot a 2,100 ft continuous cement plug on top of the BHA to abandon the well. The main challenge for setting a cement plug across a horizontal section, is cement slumping and stuck pipe, which might result in repeating cement plug jobs or non-productive time having a negative impact on well economics. To achieve isolation objectives in the first attempt, this long continual plug was broken up amongst four smaller individual plugs "stacked" on top of each other. The first 3 plugs were designed to each be 600 ft in length followed by a 340 ft plug. To avoid cement slumping, a cement support tool was deployed above the BHA before the first plug in the horizontal section. The first three plugs were placed in the horizontal open hole section and the fourth plug was placed at an inclination of 75 degrees, all using the "pump and pull" method. The pump and pull method is a common practice for worker operations with coil tubing and this similar technique can be applied in ERD drilling operations to aid in the homogeneous and accurate placement of cement plugs. However, for this job, the pump and pull placement method was preferred to aid in the homogenous and accurate placement of cement slurry through the horizontal open hole section. Detailed job calculations, the slurry design which was tailored for this application along with detailed operational procedures which resulted in the successful placement of all plugs on the first attempt under challenging well conditions will all be discussed. The approach utilized here resulted in the successful placement of a 2,100 ft continuous plug which isolated the BHA and saved the project valuable rig time. Similar approaches can be used in other areas to achieve successful results in first attempts to help well economics.

Managed-Pressure Cementing in HPHT Well with Very Narrow Operating Pressure Window

2021 ◽  
Author(s):  
David Salinas Sanchez ◽  
Mario Noguez Lugo ◽  
Oscar Zamora Torres ◽  
Cuauhtemoc Cruz Castillo ◽  
Moises Muñoz Rivera ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Stopping Time ◽  
Operating Pressure ◽  
Cement Slurry ◽  
Working Pressure ◽  
Lost Circulation ◽  
Main Challenge ◽  
Fiber Technology ◽  
Open Hole ◽  
Reverse Circulation

Abstract A 7-in. liner was successfully cemented in the south east region of Mexico at 7530 m MD despite significant pressure and temperature challenges. The entire 1,370-m, 8.5" open hole section needed cement coverage and isolation to test several intervals. The challenge of the ultranarrow working pressure window was overcome by using managed pressure cementing (MPC) along with lost circulation solutions for the cement slurry and spacer. Due to the narrow pressure window (0.05 g/cc density gradient), mud losses could not be avoided during the cementing job. To limit and manage losses, an MPC placement technique was proposed, in conjunction with using lost circulation fiber technology in the cement slurry and spacer. After addressing the losses and narrow working pressure window, the next main challenge was the extremely high temperature (Bottom hole static temperature of 171°C). Extensive lab testing provided the fluid solution: HT formulations for cement slurry and spacer to maintain stability and rheology for placement and management of equivalent circulating density and set cement properties for long-term zonal isolation. After the liner was run to bottom, the mud density was homogenized from 1.40 g/cc to 1.30 g/cc (pore pressure: 1.38 g/cc). During this process, 32.5 m3 of mud was lost to the formation. During the previous circulation, the backpressure required to maintain the equivalent circulation density (ECD) above pore pressure, which was calculated and validated resulting in 1,100 psi annulus surface pressure (close to the limit of the equipment capacity) during the stopping time. The cementing job was pumped flawlessly with only 10 m3 of mud loss at the end of the job. During reverse circulation, contaminated spacer at surface indicated no cementing fluid had been lost to the formation and adequate open-hole coverage. The liner was successfully pressure tested to 4,500 psi, and cement logs showed that the cement had covered the open hole completely. MPC is not a conventional cementing technique. After the successful result on this job and subsequent operations, this technique is now being adopted to optimize cementing in even deeper wells in Mexico, where losses during cementing operations in the past had modified or limited the whole well construction and designed completion, and production of the well.

Infill Depleted Gas Well Cementing Challenges for Offshore Myanmar Drilling Operations

2021 ◽  
Author(s):  
Ajita Ang C K Ang ◽  
Avinash A Kumar Kumar ◽  
Syazwan B A Ghani Ghani ◽  
Nann N N Maung Nann ◽  
M Hanif Yusof Yusoff ◽  
...  
Keyword(s):  
Water Production ◽  
Cement Slurry ◽  
Water Contact ◽  
Gas Well ◽  
Well Drilling ◽  
Depletion Rate ◽  
Open Hole ◽  
Drilling Operations ◽  
Sensitivity Studies ◽  
Remedial Work

Abstract Infill well drilling was planned and executed to increase production in a significantly depleted field. A total of 3 infill wells were drilled in 2 different layers of reservoir for an offshore operator in Myanmar. In the offset wells, water production had become significantly higher throughout. Previously all offset wells in this field were completed with open hole sand screens was chosen to isolate the water bearing sand in the sand reservoir below. Pore pressure prognosis were calculated from offset well depletion rate. Reservoir formation properties is assumed to be same throughout the field. The first well was drilled and was found that there were two gas water contacts through the 3 targeted sand layers. The gas water contact and WUT (Water Up To) in this well were unexpected and it was prognosed that these gas water contact are there due to compartmentalization. The 7" liner were set and cemented throughout these reservoirs. The cement job went as per the plan and there were no losses recorded during cementing. However, initial cement log did not show isolation. 2 more runs of cement log were performed 6 days and 10 days later while conducting intervention activities on other wells. All three cement log came to the same conclusion, showing no isolation throughout the annulus of the 7" production liner. Significant amount of gas had percolated into the annulus over time. Despite no evidence of poor cement slurry design observed during running various sensitivity studies and post-job lab tests final cement log, which was conducted under pressure and confirmed no hydraulic isolation. A cement remedial job was planned and an investigation was conducted to identify the plausible root causes. This paper explains on the root causes of poor cement presence in the annulus, and the remedial work that took place to rectify the issue.

Using Computer Simulations to Aid the Analysis of Fluid Contaminations During Cement Plug Placement

2021 ◽  
Author(s):  
Shuai Wang ◽  
Hu Dai ◽  
Liang He
Keyword(s):  
Computer Program ◽  
Computer Simulations ◽  
Traditional Method ◽  
Fluid Level ◽  
Cement Slurry ◽  
Wellbore Integrity ◽  
Pull Out ◽  
Drilling Operations ◽  
Cement Plug

Abstract Setting a cement plug on the target zone either creates a solid seal to stop fluid movement or provides a kick-off point for sidetrack drilling operations. Successfully placing cement plugs is one of most critical steps to ensure trouble free completion, reduce the risk of loss of circulation, isolate pressure zones and enhance wellbore integrity. The traditional method is to pump all the fluids until each fluid level is equal to that inside the string. The limitation to this method is that the fluid could be contaminated once the string is pulled out of the hole, due to variable fluid densities, as well as wellbore and work string sizes. Thus, the volume of spacers pumped ahead and behind the cement and the volume of displacement are critical to the quality of the cement plug. A computer program is developed to model the displacement hydraulics of fluids and simulate fluids contamination during pulling pipe out of hole. The computer modeling aids in optimizing the pumping schedule to ensure balanced slurry and spacer levels after POOH (Pull out of the hole), minimizing contamination within the cement slurry and spacer, ultimately, reducing the risk of loss of circulation and enhancing wellbore integrity.

Long Horizontal Well Completion via a New Flotation Technique

2021 ◽  
Author(s):  
Youngbin Shan ◽  
Hongjun Lu ◽  
Qingbo Jiang ◽  
Zhijun Li ◽  
Jianpeng Xue ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Oil And Gas ◽  
New Technology ◽  
New Technique ◽  
Hydraulic Pressure ◽  
Horizontal Section ◽  
Well Completion ◽  
Horizontal Length ◽  
Open Hole ◽  
Negative Effect

Abstract The objective of the paper is to introduce a new technology which secures long horizontal casing deployment by a reliable casing flotation technology. It is common nowadays to drill a slim hole and extends to long horizontal extension to pay zones in condensate and shale oil and gas reservoir. To assure a successful casing deployment into the horizontal section, a flotation collar is often installed to float the casing in horizontal to mitigate the friction and Torque & Drag. However, slim casing may encounter difficulty in circulation and subsequent cementing even after the collar is broken. A new proprietary technique proposed in this paper solved above contingencies and secured 100% success in casing deployment, This technique secures smoothly circulation and cementing by flotating air in horizontal casing interval and purging air out of hole to overcome Spring Effect before circulation and cementing. Often, the flotation collar is made of proprietary material that can break or explodes under certain hydraulic pressure. After breaking, the whole collar becomes a portion of casing with exact the same ID of casing or a very small difference that does not have any negative effect to subsequent Plug & Perf, frac, tools running through and fluid movement. For long horizontal length of small open hole and casing sizes, casing deployment may be difficult if the Torque & Drag and friction through the low sides can not be mitigated. This paper proposes a new technique to fill air full of horizontal interval along inside the casing and ensure a sufficient of air purging to overcome Spring Effect before circulation and cementing. So far twelve (12) wells have been successfully completed including Asian longest horizontal gas well with 7,388.18m measured depth and 4,118.18m horizontal length. All jobs are 100% successful and there is no difficulty in mud circulation and cementing. Even for the longest 4,118.18m horizontal length casing deployment, the hook weight on surface when casing reached the total depth still remained 20 MT. Before this technique was applied, operators were unable to deploy 4 ½" casing through a 6" bit hole beyond 1500m horizontal length. Most often the hook weight at surface were zero when casing extended to almost 1500m in horizontal length. This new technique brings a great value to operators to complete longer horizontal well to yield more production with less investment.

scholarly journals Path Planning for Mobile-Anchor Based Wireless Sensor Networks Localization: Obstacle-Presence Schemes

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3697
Author(s):  
Dogan Yildiz ◽  
Serap Karagol
Keyword(s):  
Path Planning ◽  
Negative Impact ◽  
Wireless Sensor ◽  
Localization Accuracy ◽  
Planning Models ◽  
Main Challenge ◽  
Current Location ◽  
Proposed Model ◽  
Logical Method ◽  
Weighted Centroid Localization

In many Wireless Sensor Network (WSN) applications, the location of the nodes in the network is required. A logical method to find Unknown Nodes (UNNs) in the network is to use one or several mobile anchors (MAs) equipped with GPS units moving between UNNs and periodically broadcast their current location. The main challenge at this stage is to design an optimum path to estimate the locations of UNNs as accurately as possible, reach all nodes in the network, and complete the localization process as quickly as possible. This article proposes a new path planning approach for MA-based localization called Nested Hexagon Curves (NHexCurves). The proposed model’s performance is compared with the performance of five existing static path planning models using Weighted Centroid Localization (WCL) and Accuracy Priority Trilateration (APT) localization techniques in the obstacle-presence scenario. With the obstacle-handling trajectories used for the models, the negative impact of the obstacle on the localization is reduced. The proposed model provides full coverage and high localization accuracy in the obstacle-presence scenario. The simulation results show the advantages of the proposed path planning model with the H-curve model over existing schemes.

Horizontal Well Penetration Rate Increasing Technology in Sulige Gas Field

2015 ◽  
Vol 733 ◽  
pp. 17-22
Author(s):  
Yang Liu ◽  
Zhuo Pu He ◽  
Qi Ma ◽  
Yu Hang Yu
Keyword(s):  
Horizontal Well ◽  
Economies Of Scale ◽  
Reference Value ◽  
Drilling Speed ◽  
Underground Engineering ◽  
Gas Field ◽  
Horizontal Section ◽  
Well Drilling ◽  
Drilling Parameters ◽  
Key Techniques

In order to improve the drilling speed, lower the costs of development and solve the challenge of economies of scale development in sulige gas field, the key techniques research on long horizontal section of horizontal well drilling speed are carried out. Through analyzing the well drilling and geological data in study area, and supplemented by the feedback of measured bottom hole parameters provided by underground engineering parameters measuring instrument, the key factors restricting the drilling speed are found out and finally developed a series of optimum fast drilling technologies of horizontal wells, including exploitation geology engineering technique, strengthen the control of wellbore trajectory, optimize the design of the drill bit and BHA and intensify the drilling parameters. These technologies have a high reference value to improve the ROP of horizontal well in sulige gas field.

scholarly journals Prediction of water breakthrough time in horizontal Wells in edge water condensate gas reservoirs

2020 ◽  
Vol 213 ◽  
pp. 02009
Author(s):  
Quan Hua Huang ◽  
Xing Yu Lin
Keyword(s):  
Horizontal Well ◽  
Negative Impact ◽  
Horizontal Wells ◽  
Breakthrough Time ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Water Breakthrough ◽  
Calculation Results ◽  
Seepage Model ◽  
Reasonable Prediction

Horizontal Wells are often used to develop condensate gas reservoirs. When there is edge water in the gas reservoir, it will have a negative impact on the production of natural gas. Therefore, reasonable prediction of its water breakthrough time is of great significance for the efficient development of condensate gas reservoirs.At present, the prediction model of water breakthrough time in horizontal Wells of condensate gas reservoir is not perfect, and there are mainly problems such as incomplete consideration of retrograde condensate pollution and inaccurate determination of horizontal well seepage model. Based on the ellipsoidal horizontal well seepage model, considering the advance of edge water to the bottom of the well and condensate oil to formation, the advance of edge water is divided into two processes. The time when the first water molecule reaches the bottom of the well when the edge water tongue enters is deduced, that is, the time of edge water breakthrough in condensate gas reservoir.The calculation results show that the relative error of water breakthrough time considering retrograde condensate pollution is less than that without consideration, with a higher accuracy. The example error is less than 2%, which can be effectively applied to the development of edge water gas reservoir.

An Innovative Approach to P&A Barrier Verification and Cement Plug Placement Utilising In-Situ Completion Strings: A Case Study

2021 ◽  
Author(s):  
Andrew Imrie ◽  
Ashikin Kamaludin ◽  
Andrew Hood ◽  
Alistair Agnew
Keyword(s):  
Evaluation Criteria ◽  
Innovative Approach ◽  
Bond Quality ◽  
Cement Slurry ◽  
Additional Time ◽  
Time Saving ◽  
Deviation Analysis ◽  
Degree Deviation ◽  
Cement Plug

Abstract Traditional evaluation of behind-casing cement bond quality prior to cement plug placement involves removal, storage, transportation, and disposal of the tubing completion string. This paper presents an innovative approach to verifying cement bond and subsequent cement plug placement. This method involves cutting and retrieving part of the completion string and deploying acoustic logging tools into the casing, followed by using the tubing as a cement stinger. The procedure described in this paper first involves plugging and cutting the tubing, followed by partial retrieval of the completion to expose the abandonment horizon, which may be an impermeable shale or salt layer. A radial cement bond log tool is conveyed on wireline out of the tubing cut in order to evaluate the cement bond behind the exposed casing section. The existing cement sheath is assessed in accordance to a cement evaluation criteria to determine suitability as a barrier. A balanced cement plug is pumped utilising the existing completion string rather than a dedicated stinger. The permanent barrier is then verified appropriately based on satisfying key metrics in the pumping operation before hanging off the completion tubing in-hole and progressing with the rest of the abandonment programme. In the case study presented here, the tool string design considered the need to pass completion restrictions, convey through production tubing, and remain centralised with up to 50-degree deviation. Analysis of cement bond log data indicated that bond quality was good and suitable to place an internal cement plug across the abandonment horizon. This satisfied a minimum of 200-ft coverage across the zone of interest. The existing deep-set mechanical plug placed in the tubing prior to tubing cut was utilised as a base for the cement barrier. A 2,000-ft balanced cement plug was successfully set across the zone of interest. The completion tubing was used as a conduit for cement slurry placement, eliminating the usage of a dedicated work string. At the end of displacement, the tubing string was pulled out of hole safely to approximately 500-ft above the top of the cement with the help of controlled-gel progression properties incorporated in the slurry design. Due to existing completion accessories, setting a through-tubing cement plug and tubing rotation is not an option. Expandable cement was pumped to mitigate natural shrinkage and enhance post-set cement expansion to ensure a competent barrier. The cement job objectives were achieved by meeting the cementation execution criteria with no requirement to wait on cement. This provides additional time saving to the well abandonment. The discussed approach has successfully realised a significant rig-time saving of approximately two days on each well. Going forward, the methodology has effectively been applied to multiple wells across the Southern North Sea (SNS).

Successful CWD Campaign in Turnkey Project with Potential Utilisation for Well Construction Optimisation

2021 ◽  
Author(s):  
Louis Frederic Antoine Champain ◽  
Syed Zahoor Ullah ◽  
Alexey Ruzhnikov
Keyword(s):  
Cost Effective ◽  
Drill String ◽  
Successful Implementation ◽  
Delivery Time ◽  
Wellbore Instability ◽  
Third Phase ◽  
Drilling Parameters ◽  
Open Hole ◽  
Bottom Hole Assembly ◽  
Full Throttle

Abstract Drilling and completion of the surface and intermediate sections in some fields is extremely challenging due to wellbore instability, especially accomplished with complete losses. Such circumstances lead to several time-consuming stuck pipe events, when existing standard ways of drilling did not lead to a permanent resolution of the problems. After exhausting the available conventional techniques without sustainable success, unorthodox solutions were required to justify the well delivery time and cost. Here comes the Casing While Drilling (CwD), being the most time and cost-effective solution to wellbore instability. CwD is introduced at full throttle aiming at the well cost reduction and well quality improvement. The implementation plan was divided in three phases. The first phase was a remedial solution to surface and intermediate sections drilling and casing off to prevent stuck pipe events and provide smooth well delivery performances. After successful implementation of CwD first phase, CwD was taken to the next level by shifting it from a mitigation to an optimization measure. Each step of CwD shoe-to-shoe operations was analysed to improve its performances: drill-out (D/O) of 18⅝-in shoe track with CwD, optimum drilling parameters per formation and CwD bit design. Implemented in 19 wells, CwD shoe-to-shoe performances have been brought up or even above standard rotary bottom hole assembly (BHA) benchmark. Planning for third phase is undergoing whereby CwD is aiming to optimize a well construction to reduce well delivery time, by combining surface and intermediate sections thus eliminating one casing string. Numerous challenges are being worked on including open hole (OH) isolation packer which conform to and seal with the borehole uneven surface. Special "for purpose built" expandable steel packer and stage tool have been manufactured and qualified for the specific application. A candidate well has been chosen and agreed for first trial. The key areas of improvement include, drilling and casing off the surface and intermediate sections while competing with standard rotary BHA performances and slimming down the well profile towards tremendous time and costs savings. This paper encompasses details of constructions of various wells with sufficient contingencies to combat any expected hole problems without compromising the well quality while keeping the well within budget and planned time. It also provides an analysis of the well trials that were executed during the implementation of first and second phases of CwD implementation and the captured lessons learnt which are being carried forward to the next phase. This paper provides the technique on how CwD can be used to help with three aspects of drilling, successfully mitigating holes problems by reducing OH exposure time and to eliminate drill string tripping and modifying conventional casing design to reduce well time and cost by eliminating one casing string.

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.

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