## Abstract

A new technique has been developed to estimate the

temperature increase during cement hydration. The

method presented in this article will enable to select

the optimal time lapse between cement placement

and temperature survey. A semi-analytical equation

was earlier suggested which describes the transient

temperature at the borehole’s wall, while the radial

heat flow rate (into formations) is a quadratic

function of time. Only field or laboratory heat

production rate – time data are needed to calculate

the transient values of the temperature increase. Two

field examples of cement hydration when retarders

were used are presented in the article. Assessment of

the temperature development during hydration is

necessary to determine how fast the cement will

reach an acceptable compressive strength before the

casing can be released. Therefore, for deep wells

heat generation during cement hydration has to be

taken into account at cement slurry design. The

experimental data show that the maximum value of

heat generation occurs during the first 5 to 24 hours.

During this period the maximum temperature

increase (ΔTmax) can be observed in the annulus. In

order to evaluate the temperature increase during

cement hydration it is necessary to approximate the

heat production versus time curve by some analytical

function. It was found that a quadratic equation can

be used for a short interval of time to approximate the

rate of heat generation (q) per unit of length as a

function of time. Temperature surveys following the

cementing operation are used for locating the top of

the cement column behind casing. Field experience

shows that in some cases the temperature anomalies

caused by the heat of cement hydration can be very

substantial. However, even in such cases it is very

important to predict the temperature increase during

the cement setting. This will enable to determine the

optimal time lapse between cementing and

temperature survey. Below we present a semianalytical formula which will allow one to estimate

the temperature increase versus setting time

(Kutasov, 2007). This formula describes the transient

temperature at the cylinder's wall (Tv), while at the

surface of the cylinder the radial heat flow rate (into

formations) is a quadratic function of time.

temperature increase during cement hydration. The

method presented in this article will enable to select

the optimal time lapse between cement placement

and temperature survey. A semi-analytical equation

was earlier suggested which describes the transient

temperature at the borehole’s wall, while the radial

heat flow rate (into formations) is a quadratic

function of time. Only field or laboratory heat

production rate – time data are needed to calculate

the transient values of the temperature increase. Two

field examples of cement hydration when retarders

were used are presented in the article. Assessment of

the temperature development during hydration is

necessary to determine how fast the cement will

reach an acceptable compressive strength before the

casing can be released. Therefore, for deep wells

heat generation during cement hydration has to be

taken into account at cement slurry design. The

experimental data show that the maximum value of

heat generation occurs during the first 5 to 24 hours.

During this period the maximum temperature

increase (ΔTmax) can be observed in the annulus. In

order to evaluate the temperature increase during

cement hydration it is necessary to approximate the

heat production versus time curve by some analytical

function. It was found that a quadratic equation can

be used for a short interval of time to approximate the

rate of heat generation (q) per unit of length as a

function of time. Temperature surveys following the

cementing operation are used for locating the top of

the cement column behind casing. Field experience

shows that in some cases the temperature anomalies

caused by the heat of cement hydration can be very

substantial. However, even in such cases it is very

important to predict the temperature increase during

the cement setting. This will enable to determine the

optimal time lapse between cementing and

temperature survey. Below we present a semianalytical formula which will allow one to estimate

the temperature increase versus setting time

(Kutasov, 2007). This formula describes the transient

temperature at the cylinder's wall (Tv), while at the

surface of the cylinder the radial heat flow rate (into

formations) is a quadratic function of time.

Original language | American English |
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Title of host publication | Thirty-eighth Workshop on Geothermal Reservoir Engineering |

Place of Publication | Stanford |

Pages | 1-6 |

State | Published - 2013 |

Event | Stanford Geothermal Workshop - Stanford, California Duration: 30 Jan 2013 → 1 Feb 2013 |

### Conference

Conference | Stanford Geothermal Workshop |
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City | California |

Period | 30/01/13 → 1/02/13 |