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 |
|---|---|
| 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 |
|---|---|
| City | California |
| Period | 30/01/13 → 1/02/13 |