RECOVERY OF OIL WELL TO EXTRACT GEOTHERMAL WATERS FROM LIMESTONE AQUIFER FOR GREENHOUSE HEATING

Objetivo

To investigate geothermal possibilities, for low enthalpy operations of the carbonate aquifer "Calizas de Subijana" and utilization of this energy in the heating of greenhouses destinated to the production of cut flowers and green plants. The project is the first geothermal exploration ever carried out in the Basque region.
The project had to define the physical and chemical characteristics of the geothermal fluid, and the exploration parameters.
Antezana-1 is a very productive geothermal well and could give 300 m3/h pump assisted flowrate but the aquifer temperature is too low commercial exploitation.
The geothermal water is only 10-15 years old and the water circulation speed of 1 to 1.4 m/day match with the variation of static level according to the rain.
Geochemistry proves that no element founded in the water analysis can be transported at a temperature higher than of the captation temperature.
Limestone porosity (till 20%) storage coefficient and high transmissivity demonstrate the good capacity of this aquifer.
The recovery of the 25 years old well was carried out in March-April 1987.
The operations were : drilling of cement plugs and accondionated the old well. Milling the 9" 5/8 casing between 1726 m and 1742 m, widening of this interval to 12" 1/4, side-tracking (12 deg. angle) to a final depth of 2093 m in 6". The casing of the original well was plugged with cement at 1742 m. The final section of the well is :
casing 13"3/8 at 284m.
Casing 9"5/8 at 1726m.
Open hole at T.D. 2093 m.
Production levels are located in Subijana Limestone Formation, this formation was acidified (24 m3) and tested by means of air-lift. The reservoir showed the following characteristics :
Aquifer net pay. - 37.3 m
Average porosity. - 13%
Flow rate. - 160 m3/h for a drawdown of 58 m
Salinity. - 0.3 gr/l
Transmissivity. - 310 D.m
Skin. - +10.55
Static level. - 55 m.
The maximum temperature recorde in the well was 18.9 deg. C at 2085 m and 16-17 deg. C on the surface.

Programa(s)

ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989

Tema(s)

4.1 - HEATING

Convocatoria de propuestas

Data not available

Régimen de financiación

DEM - Demonstration contracts

Coordinador

ENTE VASCO DE LA ENERGIA

Aportación de la UE

Sin datos

Dirección

EDIFICIO ALBIA 1, PL 14
48001 Bilbao
España

Coste total