IADC/SPE DRILLING CONFERENCE: CEMENTING & … T Aguilar, ExxonMobil; DT Mueller, D Doherty, ......
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KILLING AND CEMENTING DRILLING WITH CASING has been used in South Texas to reduce costs. Underbalanced drilling seems to have the potential to eliminate an intermedi- ate casing string. By drilling underbal- anced, it would be possible to drill with a mud weight low enough to prevent loss of circulation in the shallow weak zones while dealing with the gas from the pay zones below. Drilling with cas- ing eliminates the necessity of trips. However, once TD was reached, it would be necessary to balance the well to allow cementing of the production casing string. The challenge was to develop a way to kill the well so that the cement could be placed and allowed to set while at the same time not breaking down and losing circulation into the weak upper zones. This had to be done by having different equivalent circulating densities and equivalent mud weights up and down the hole throughout the circulating and cementing operation. This paper describes the development of the required methodology and its successful field application. Simultaneous Dynamic Killing and Cementing of a Live Well (IADC/SPE 98440) PA Solano, Halliburton; R Strick- ler, ConocoPhilips; DD Moore, Signa Engineering Corp. DEEP GAS WELL CEMENTING This paper discusses the risk analysis and development plan that led to the selection of a liquid cement premix for large-volume jobs. The paper covers the design requirements of the jobs and addresses the risks associated with the available options. Information is provid- ed on risks associated with boat and barge stability, draft limits at available bulk facilities, deck load limits and logis- tics of alternate designs. The paper further covers the equipment requirements and mixing needs and compares the selected option to that of a conventional cement job. Deep Gas Well Cementation: A Review of Risks and Design Basis for Use of a Liquid Cement Premix for Large Off- shore Cementing Operations (IADC/SPE 98970) G Benge, JB Darby, M Peroyea, T Aguilar, ExxonMobil; DT Mueller, D Doherty, BJ Services. CEMENT DESIGNS Pressure events that occur after surface casing cementation impose stress on the cement sheath. If pressure testing takes place early in cement curing, the tangen- tial stress imposed may exceed the ten- sile strength of the cement, thereby inducing cement sheath failure. In most wellbore pressure scenarios, the cement sheath fails in tension. The pro- portionality between the compressive strength and the tensile strength of set cement is generally assumed to be a 10:1 ratio. In surface casing applications, the time at which induced pressure events occur may be as low as 8 to 12 hours after the cementing operation. In this time frame, the cement will have a compressive strength ranging from that required for the commencement of drilling operations (500 psi) to upwards of 1,500 psi. Accordingly, conventional wisdom would hold that the tensile strength of the cement would be in the range of 50 to 150 psi. Is this assumption correct? This paper characterizes the early state physical properties and mechanical behavior of accelerated Type I, Class A, G, and H cement designs during the 12 hours after placement. Characterization of the Early Time Mechanical Behavior of Well Cements Employed in Surface Casing Opera- tions (IADC/SPE 98632) DT Mueller, RN Eid, BJ Services. ULTRA-HIGH TEMPERATURES The ability of a cement sheath to remain intact when exposed to changing well- bore stresses is highly dependent on the parameters of Young’s Modulus, Pois- son’s Ratio and tensile strength of the cement and the surrounding rock. Wells subjected to Cyclic Steam Stimula- tion (CSS) for heavy oil recovery undergo extreme temperature changes. During CSS, wellbore temperatures can fluctu- ate between 77 deg F and 645 deg F. 44 D R I L L I N G CONTRACTOR January/February 2006 Cementing method enhances well killing IADC/SPE DRILLING CONFERENCE: CEMENTING & ZONAL ISOLATION 98896: In tests measuring the mechanical parameters of five cement formulations after exposure to a temperature of 645 degrees Fahrenheit, the temperature conditions to which the cement was exposed was found to have a significant impact on the mechanical parameters. The mechanical parameters of systems exposed to 645 degrees varied significantly from systems exposed to an ambi- ent temperature of 77 degrees.
Transcript of IADC/SPE DRILLING CONFERENCE: CEMENTING & … T Aguilar, ExxonMobil; DT Mueller, D Doherty, ......
K I L L I N G A N D C E M E N T I N G
DRILLING WITH CASING has beenused in South Texas to reduce costs.Underbalanced drilling seems to havethe potential to eliminate an intermedi-ate casing string. By drilling underbal-anced, it would be possible to drill witha mud weight low enough to preventloss of circulation in the shallow weakzones while dealing with the gas fromthe pay zones below. Drilling with cas-ing eliminates the necessity of trips.However, once TD was reached, itwould be necessary to balance the wellto allow cementing of the productioncasing string.
The challenge was to develop a way tokill the well so that the cement could beplaced and allowed to set while at thesame time not breaking down and losingcirculation into the weak upper zones.This had to be done by having differentequivalent circulating densities andequivalent mud weights up and down thehole throughout the circulating andcementing operation. This paperdescribes the development of therequired methodology and its successfulfield application.
Simultaneous Dynamic Killing andCementing of a Live Well (IADC/SPE98440) PA Solano, Halliburton; R Strick-ler, ConocoPhilips; DD Moore, SignaEngineering Corp.
D E E P G A S W E L L C E M E N T I N G
This paper discusses the risk analysisand development plan that led to theselection of a liquid cement premix forlarge-volume jobs. The paper covers thedesign requirements of the jobs andaddresses the risks associated with theavailable options. Information is provid-ed on risks associated with boat andbarge stability, draft limits at availablebulk facilities, deck load limits and logis-tics of alternate designs.
The paper further covers the equipmentrequirements and mixing needs andcompares the selected option to that of aconventional cement job.
Deep Gas Well Cementation: A Reviewof Risks and Design Basis for Use of aLiquid Cement Premix for Large Off-shore Cementing Operations(IADC/SPE 98970) G Benge, JB Darby, M
Peroyea, T Aguilar, ExxonMobil; DTMueller, D Doherty, BJ Services.
C E M E N T D E S I G N S
Pressure events that occur after surfacecasing cementation impose stress on thecement sheath. If pressure testing takesplace early in cement curing, the tangen-tial stress imposed may exceed the ten-sile strength of the cement, therebyinducing cement sheath failure.
In most wellbore pressure scenarios, thecement sheath fails in tension. The pro-portionality between the compressivestrength and the tensile strength of setcement is generally assumed to be a 10:1ratio. In surface casing applications, thetime at which induced pressure eventsoccur may be as low as 8 to 12 hoursafter the cementing operation.
In this time frame, the cement will have acompressive strength ranging from thatrequired for the commencement of drillingoperations (500 psi) to upwards of 1,500psi. Accordingly, conventional wisdomwould hold that the tensile strength of the
cement would be in the range of 50 to 150psi. Is this assumption correct?
This paper characterizes the early statephysical properties and mechanicalbehavior of accelerated Type I, Class A,G, and H cement designs during the 12hours after placement.
Characterization of the Early TimeMechanical Behavior of Well CementsEmployed in Surface Casing Opera-tions (IADC/SPE 98632) DT Mueller, RNEid, BJ Services.
U L T R A - H I G H T E M P E R A T U R E S
The ability of a cement sheath to remainintact when exposed to changing well-bore stresses is highly dependent on theparameters of Young’s Modulus, Pois-son’s Ratio and tensile strength of thecement and the surrounding rock.
Wells subjected to Cyclic Steam Stimula-tion (CSS) for heavy oil recovery undergoextreme temperature changes. DuringCSS, wellbore temperatures can fluctu-ate between 77 deg F and 645 deg F.
44 D R I L L I N G C O N T R A C T O R January/February 2006
Cementing method enhances well killing
IADC/SPE DRILLING CONFERENCE: CEMENTING & ZONAL ISOLATION
98896: In tests measuring the mechanical parameters of five cement formulations after exposure toa temperature of 645 degrees Fahrenheit, the temperature conditions to which the cement wasexposed was found to have a significant impact on the mechanical parameters. The mechanicalparameters of systems exposed to 645 degrees varied significantly from systems exposed to an ambi-ent temperature of 77 degrees.
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Various Finite Element Analysis modelsrequire input of cement mechanicalparameters. But no mechanical parame-ters are made after long-term exposureof the cement to the ultra-high tempera-tures encountered in CSS wells.
This paper presents a test methodologyfor measuring the mechanical parame-ters of five cement formulations afterexposure to a temperature of 645 deg F.
Effects of Long Term Exposure toUltrahigh Temperature on the Mechan-ical Parameters of Cement (IADC/SPE98896) D Stiles, ExxonMobil.
E X T R E M E S T R E S S E S
The deep Bossier formations of the EastTexas Hilltop Field encounter low per-meability gas bearing formations at over15,000 psi and 400 deg F. Wellbore tem-perature variations occurring betweenstimulation and production operationsare extreme. Two of the first three wellscompleted in this area failed via casingcollapse.
Analysis confirmed that the extremestresses being applied to these wells ren-dered the previous casings and cementsheaths as underdesigned. Detailed ther-mal and mechanical modeling of all well-bore operations resulted in redesignedcasings.
High-strength, corrosion-resistant cas-ings and specialty cement designs weresuccessfully used. All of the wells havewithstood stimulations at treating pres-sures exceeding 14,000 psi, productiondrawdowns of over 13,000 psi, and tem-perature changes estimated at over 300degrees F.
Finite Element Analysis Couples Cas-ing and Cement Designs for HT/HPWells in East Texas (IADC/SPE 98869)JF Heathman, Halliburton; F Beck, Gas-tar Exploration Ltd.
P R E V E N T I N G C O 2 M I G R A T I O N
A leaking wellbore annulus can be apathway for CO2 migration intounplanned zones.
With the lack of industry standard prac-tices dealing with wellbore isolation forthe time scale of geological storage, amethodology to mitigate the associatedrisks is required. This requirement led tothe need and development of a laborato-ry qualification of resistant cements andthe long-term modeling of cement sheetintegrity.
This article presents the results of acomprehensive study on the degradationof cement in simulating the interaction ofthe set cement with injected supercriticalCO2 under downhole conditions.
Mitigation Strategies for the Risk ofCO2 Migration Through Wellbores(IADC/SPE 98924) V Barlet-Gouedard,TS Ramakrishnan, Schlumberger; GRimmele, B Goffe, ENS/CNRS.
C E M E N T D U R A B I L I T Y
It’s estimated that 40 percent of theworld’s remaining gas reserves contain aCO2 content higher than 2 percentand/or a H2S content higher than 100ppm. Therefore, special attention has tobe paid to the design of well materials.
This paper addresses the problem ofdurability of oilwell cement in differenthydrogen sulphide environments.
In this paper, we present the methodolo-gy implemented under HP/HT conditionsfor aging tests of materials in H2S-con-taining fluids and results obtained oncement-based materials.
Durability of Oilwell Cement Formu-lations Aged in H2S Containing Fluids(IADC/SPE 99105) E Lecolier, A
Rivereau, A Audibert-Hayet, X Lon-gaygue, Inst Francais du Petrole.
C E M E N T I N G D I S P O S A L W E L L
This paper will discuss the design, exe-cution and evaluation of a dedicatedinjector well in the Grane field in the Nor-wegian North Sea for an application forstress modeling and a new sealant.
Stress modeling indicated that conven-tional cement would fail in tension. Theteam redesigned the cement programincorporating stress analysis calcula-tions and mechanical properties testingto provide a sealant material that wouldresist failure due to excessive wellborestresses. The chosen sealant materialincorporated flexible and expandingmaterials within an optimized particlesize distribution blend.
The well has been logged with sonic andultrasonic tools and has indicated anexcellent bonding response.
Cementing of an Offshore DisposalWell Using a Novel Sealant That With-stands Pressure and TemperatureCycles (IADC/SPE 98891) CR Johnson, ETherond, Schlumberger; C Scheie,Hydro; R Pedersen, Hydro. �
46 D R I L L I N G C O N T R A C T O R January/February 2006
IADC/SPE DRILLING CONFERENCE: CEMENTING & ZONAL ISOLATION
98891: A dedicated injector well was chosen as an application for stress modeling and a novel newsealant. Stress modeling indicated that as wellbore temperature decreased from bottomhole staticto injection temperature, and bottomhole pressure cycled between static and dynamic conditions,conventional cement would fail in tension and create a microannulus. In view of these challenges,the team in charge of cementing the well decided to redesign the cement program incorporatingstress analysis calculations and mechanical properties testing to provide a sealant material thatwould resist failure due to excessive wellbore stresses.
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