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

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.

Double Casing Exit for Side-Track to Commingle Two Borehole Sizes Based Sections in One Slim Shot to Well TD

2021 ◽  
Author(s):  
Meshal Al-Khaldi ◽  
Dhari Al-Saadi ◽  
Mohammad Al-Ajmi ◽  
Abhijit Dutta ◽  
Ibrahim Elafify ◽  
...  
Keyword(s):  
Challenging Behaviors ◽  
Single Shot ◽  
Close Monitoring ◽  
Drilling Parameters ◽  
Wellbore Pressure ◽  
Open Hole ◽  
Zonal Isolation ◽  
Side Track ◽  
First Time

Abstract This project began when a 9-5/8" in 43.5 ppf production casing became inaccessible due to the existing cemented pipe inside, preventing further reservoir section exposure and necessitating a mechanical side-track meanwhile introducing the challenge of loosing one section and imposimg slim hole challenges. The size and weight of the double-casing made for challenging drilling, as did the eight very different formations, which were drilled. The side-track was accomplished in two steps, an 8½ in hole followed by a single long 6⅛ in section, rather than the three steps (16 in, 12¼ in, 8½ in) that are typically required. The optimal kick off point carfully located across the dual casing by running electromagnetic diagnostics, the casing collar locator, and the cement bond log. The double casing mill was carefully tailored to successfully accomplish the exit in one run. Moreover, an extra 26 ft. MD rathole was drilled, which helped to eliminate the mud motor elongation run. A rotary steerable system was utilized directly in a directional BHA to drill an 8½ in open hole building section from vertical to a 30⁰ inclination. A 7.0 in liner was then set to isolate weak zones at the equivalent depth of the outer casing (13-3/8"). Subsequently, a single 6⅛ in section was drilled to the well TD through the lower eight formations. Drilling a 6⅛ in section through eight formations came with a variety of challenges. These formations have different challenging behaviors relative to the wellbore pressure that typically leads to the drilling being done in two sections. Modeling the geo-mechanical characteristics of each formation allowed the determination of a mud weight range and rheology that would stabilize the wellbore through all eight formations. The slim, 6⅛ in, hole was stabilized with higher equivalent circulating density (ECD) values than is typically used in larger boreholes. Optimizing mud weight and drilling parameters, while managing differential sticking with close monitoring of real-time ECD, helped to stabilize the high-pressurized zones to deliver the well to the desired TD with a single borehole. This project represents the first time in Kuwait that double casings in such large sizes have been cut and sidetracked. It is also the first time these eight formations have been cut across such a smaller hole size, slim hole (6⅛ in) in a single shot. Geo-mechanical modeling allowed us to stabilize the pressurized formations and to control the ECD. The well also deployed the longest production liner in the field commingling multiple reservoirs with differnt pore pressure ramps, with excellent cement quality providing optimal zonal isolation.

Game Changing Cementless Annular Isolation Improving Economical Returns in Deep Water Wells

2021 ◽  
Author(s):  
Manfred Bledou ◽  
Didier Caillon ◽  
Benjamin Groschaus ◽  
Guillaume Viger ◽  
Harpal Singh ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Innovative Technology ◽  
Pressurized Water ◽  
Field Development ◽  
Increased Risk ◽  
Open Hole ◽  
Well Trajectory ◽  
Zonal Isolation ◽  
Field Deployment ◽  
The Cost

Abstract This paper will discuss a game-changing and innovative technology that enabled cementless annular isolation (liner to borehole) across the reservoir, removing the risk of previous experienced cost and time overrun from complex cement operations and securing the full economical return on the wells. The technology has been deployed in four Moho North Albian wells, drilled through a complex reservoir with highly laminated lithology requiring efficient zonal isolation for both acid treatment and water shut off. During the earlier field development, many cementing challenges were encountered that increased risk and cost and the ability to deliver effective isolation across the reservoir. Poor isolation leads to poor matrix acid stimulation, higher skin and a higher risk of water production. To address this the operator sponsored an industry challenge to achieve reservoir isolation with cost and risk reduction and to deliver overall efficiency gains. Through dialogue between the Operator and a leading service provider in Open Hole Zonal Isolation, a solution was identified that would effectively replace the cement across the reservoir with a metal expandable annular sealing system. Time for delivery was a key driver to meet the drilling schedule and materialize the cost and risk reductions on the remaining wells. A scope of work was completed that included extensive qualification, manufacture and field deployment. The solution has proven to deliver benefits that address several fundamental aspects which were associated with the cemented liners: Substantial reduction in risk and cost associated with drilling the extended rat hole (shoe track) into the highly pressurized water zone (+/- 100mMD)Removed the risk and cost for the additional run to under ream the 6 ½″ hole to 7 ¼″ (low-ROP)Provided more certainty for zonal isolation whilst delivering effective acid stimulation and maintaining the low skin values. The technology has many different applications within wells where conventional cement is challenged beyond its capabilities and inherently not fit for purpose, due to factors such as well trajectory, hole geometry, reservoir uncertainty, downhole environment (pressure, Temp, ECD) etc. Within these environments, the technology developed for Moho North adds a proven solution to the Operators toolbox, a technology that is already finding alternate applications and planned deployments.

Open Hole Packers Provide Zonal Isolation for a High Pressure Acid Stimulation within a Chalk Reservoir

2013 ◽  
Author(s):  
P. Hazel ◽  
H. Singh ◽  
J. Baardsen ◽  
R. Reves Vasques ◽  
R. Pearcy ◽  
...  
Keyword(s):  
High Pressure ◽  
Open Hole ◽  
Zonal Isolation

Metal Expandable Annular Sealing Systems for High Pressure Open Hole Zonal Isolation and Stimulation

2019 ◽  
Author(s):  
Yosafat Esquitin ◽  
Brian Schwanitz ◽  
Guido Moreno ◽  
Natalia Avella ◽  
Oscar Henao
Keyword(s):  
High Pressure ◽  
Open Hole ◽  
Zonal Isolation

A Novel Approach to Successfully Cement the Long Horizontal Liners Across Khuff-C Reservoir in High-Pressure Gas Producer Land Wells: A Case History from Saudi Arabia

2021 ◽  
Author(s):  
Wajid Ali ◽  
Freddy Jose Mata ◽  
Faisal Abdullah Al-Turki
Keyword(s):  
Drilling Fluid ◽  
Horizontal Wells ◽  
Gas Migration ◽  
Cement Slurry ◽  
Oil Companies ◽  
Temperature Modeling ◽  
Novel Approach ◽  
Open Hole ◽  
Zonal Isolation ◽  
Testing Field

Abstract Maintaining zonal isolation is vital to well economics and productive life. Well integrity is becoming more challenging with the drilling of deeper, highly deviated, and horizontal wells worldwide. Oil companies are focused on to enhance the well productivity during drilling long horizontal wells in a harsh environment by achieving maximum accessible reservoir contact. These wellbore geometries incorporate additional challenges to design and deliver a dependable barrier. In this paper, a case study about cementing the longest liner across Khuff-C reservoir has been presented discussing the main challenges, engineering considerations, field implementation, results, and conclusions. The well was drilled horizontally across Khuff-C carbonates using oil-based drilling fluid. The 5-7/8-in open hole section was planned to be cemented in single stage, utilizing 8370 ft of a 4-1/2-in liner. Careful attention was paid to estimate the bottom hole circulating temperature, using the temperature modeling simulator. A 118-lbm/ft3 slurry was designed to keep the equivalent circulation density intact. Gas migration control additives were included in the slurry design to lower the slurry's transition time, in order to reduce the chances of gas migration through the cement slurry. The slurry was batch-mixed to ensure the homogeneity of the final slurry mixture. A reactive spacer was designed to improve the cement bonding from long term zonal isolation perspective. Additionally, the spacer was loaded with optimum amounts of surfactant package to serve as an aid to remove the mud and to water-wet the formation and pipe for better cement bonding. Centralizers placement plan was optimized to allow around 63% average standoff around the pipe, staying within the torque and drag (T&D) limits. The cement treatment was performed as designed and met all zonal isolation objectives. The process of cementing horizontal liners comes with unique procedures. There are several challenges associated with carrying out wellbore zonal isolation for primary cementing of horizontal liners, therefore, a unique level of attention is required during the design and execution stages. The slurry design requires careful formulation to achieve the desired specifications while ensuring its easy deployment and placement in the liner annulus. By planning in advance and following proven techniques, many of the problems associated with the running and cementing of deep and long horizontal liners can be alleviated. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technique can be a key resource for such operations in the future. The paper describes the process used to design the liner cement job and how its application was significant to the success of the job.

Disconnect Tool Successfully and Efficiently Cements Electromagnetic Gauge Assembly in Place to Provide Key Reservoir Data

2021 ◽  
Author(s):  
Alexandru Dimcea ◽  
Iain Massie ◽  
Simon French ◽  
Dan Smith
Keyword(s):  
Data Transmission ◽  
Eastern Mediterranean ◽  
Drill String ◽  
Efficient Manner ◽  
Unique Challenge ◽  
Pilot Hole ◽  
Open Hole ◽  
Interference Test ◽  
Zonal Isolation ◽  
Software Modelling

Abstract An operator developing a deepwater field in the eastern Mediterranean required to monitor pressures in an upper sand section while producing from the main lower sands. If communication existed between the two zones, a planned late-life workover could be eliminated, reducing development cost. Gauges placed across the upper sands in a pilot hole would transmit pressure data to the production bore using electromagnetic (EM) transmission technology. Ensuring isolation of these gauges by cement was identified as critical in enabling effective EM data transmission and therefore a great deal of focus was placed on the design of the cement job. To perform the operation in as efficient manner as possible a tailored assembly was developed consisting of electronic gauges and EM relays isolated by open hole packers, along with a cementing assembly to allow cementation of the upper part of the string which included an EM receiver and relay in place. The cementing assembly consisted of a frac sleeve to allow the completion to be run and cemented in place, and a disconnect tool for the drill string to be disconnected in one run. Once disconnected from the completion, the abandonment of the pilot hole could continue without a trip out of the hole, saving significant time and costs to the operator. The cementjob design was tailored and verified by lab testing and software modelling to meet the objectives of the job and the unique challenge associated with the placement method proposed. Once the completion was installed in the production bore, communication between the gauges through the EM transmission system was confirmed and monitored during the subsequent well cleanup. The communication test verified annular isolation and system operability. Furthermore, upper and lower zonal isolation was proven by monitoring the gauge data in an interference test when flowing another well.

Sign in / Sign up

Export Citation Format

Share Document