Hole Cleaning and Cement Design for Specific Formation Types

Rueda, Francisco J.; Heathman, James; Serrano, Mario

doi:10.2118/84560-ms

Cited by 13 publications

(2 citation statements)

References 11 publications

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“…We will focus on proposing one possible explanation of why across sands (quite often permeable formations) the cement bond log is much worst than across shales (most of the time impermeable formations). This has been investigated in a few previous papers [1][2][3][4] . In those SPE/IADC 96022 Impact of Formation Type on Cement Bond Logs B. Vidick and K. Krummel, Schlumberger, and D.S.…”

Section: Introductionmentioning

confidence: 99%

Impact of Formation Type on Cement Bond Logs

Vidick

Krummel

Kellingray³

2005

All Days

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fax 01-972-952-9435. AbstractFrequently, poor cement logs are observed in low gamma ray formations (sand). Contrarily, very good bond is often noted across high gamma ray formations (shales). In some cases this has resulted in a squeeze decision where no injectivity can be obtained incurring significant costs and delayed oil. Most commonly the problem has been ascribed to an artifact of the logs, presence of mud cake, cement shrinkage and squeezing shales.However after studying many such logs the first observation is the sharp contrast between the logs

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Section: Introductionmentioning

confidence: 99%

Impact of Formation Type on Cement Bond Logs

Vidick

Krummel

Kellingray³

2005

All Days

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“…Usually, spacers and chemical washes are pumped ahead of the cement slurry for fluid separation and hole cleaning. 1,2 Ideally, the well construction process leaves a formation surface to which the cement can bond and provide zonal isolation. With respect to the formation, two processes occur prior to cementing.…”

Section: Introductionmentioning

confidence: 99%

The Cement-to-Formation Interface in Zonal Isolation

Ladva¹,

Craster²,

Jones³

et al. 2004

Proceedings of IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition

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fax 01-972-952-9435. AbstractMaintaining zonal isolation for the lifetime of oil and gas wells is critical. Leakage behind casing can reduce the costeffectiveness of the well and cause health and safety risks from pressure build-up and contaminated aquifers. During the completion and production phases of the well, temperature and pressure variations can cause stresses at the cement-toformation interface. The ability of the casing-cement system to maintain a seal at the cement-to-formation interface depends on the condition of the formation surface prior to slurry placement. The condition of a shale will depend upon the nature of the drilling fluid used, whereas the condition of a permeable rock will depend upon the presence and nature of the filtercake deposited during drilling and circulation.In this paper we present an improved understanding of chemical interactions at the cement-to-formation interface and the factors that determine bond strength and the position of the plane of failure. For permeable formations, the role of the mud filtercake for different mud types is explored. For nonpermeable formations, the presence and effect of a residual mud film are also examined. The extent and depth to which chemical alteration of the mudcake occurs when in contact with cement are determined, together with measurements of the yield stress and water content profile of the altered mudcake. The effect of exposing swelling and nonswelling shales to inhibitive drilling fluids on bond strength is presented. Laboratory-scale test equipment and a small-scale wellbore simulator, developed for tests under realistic field conditions, are described. The flexibility of cement plays a role in bonding and is demonstrated by the simulator tests. This improved understanding allows us to confirm the key issues at the cement-to-formation interface and propose some solutions for effective zonal isolation.

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