Analysis of flow data from several Baca wells

Analyses are presented of the downhole pressure buildup data for wells located in the Redondo Creek area of the Baca Geothermal Field. The downhole drilling information and pressure/temperature surveys are first interpreted to locate zones at which fluid enters the wellbore from the fractured formation and to estimate the initial reservoir temperature and pressure in these zones. Interpretation of the buildup data for each well considers wellbore effects, the CO{sub 2} content of the fluid and differentiates between the single-phase and two-phase portions of the data. Different straight-line approximations to the two portions of the data on the Horner plot for a flow test yield corresponding estimates for the single and two-phase mobilities. Estimates for the formation kh are made for the wells

Analysis of flow data from the T-F and S/DOE Gladys McCall No. 1 well. Final report

The flow and bottomhole pressure data have been analyzed for the two sands (Nos. 8 and 9) tested by the Gladys McCall No. 1 Well. The more productive sand (No. 8) appears to be bounded by two linear faults at distances of approx.740 ft and approx.1360 ft from the well and there appears to be a decrease in the formation transmissivity away from the well. The formation properties inferred from the well test analysis have been used with a reservoir simulator to match the bottomhole drawdown/buildup history measured during the Reservoir Limits Test of Sand Zone No. 8. Wellhead pressure data measured during the long-term production testing of Sand Zone No. 8 have been employed to estimate the corresponding downhole pressures. The simulation model based solely on the Reservoir Limits Test is found to be in remarkably good agreement with the estimated bottomhole pressures for the first six months of production testing, but enlargement of the reservoir volume, by moving the boundary most remote from the well outward, is required to adequately match the full production history. The added remote volume corresponds to an increase by a factor of three in the estimated reservoir volume. The results for the Gladys McCall well are discussed in the context of earlier results determined from testing the other through geopressured geothermal design wells (Pleasant Bayou No. 2, Amoco Fee No. 1 and L.R. Sweezy No. 1 Well). 12 refs., 36 figs., 7 tabs

Integrated model of the shallow and deep hydrothermal systems in the East Mesa area, Imperial Valley, California

Geological, geophysical, thermal, petrophysical and hydrological data available for the East Mesa hydrothermal system that are pertinent to the construction of a computer model of the natural flow of heat and fluid mass within the system are assembled and correlated. A conceptual model of the full system is developed and a subregion selected for quantitative modeling. By invoking the Boussinesq approximation, valid for describing the natural flow of heat and mass in a liquid hydrothermal system, it is found practical to carry computer simulations far enough in time to ensure that steady-state conditions are obtained. Initial calculations for an axisymmetric model approximating the system demonstrate that the vertical formation permeability of the deep East Mesa system must be very low (k/sub v/ approx. 0.25 to 0.5 md). Since subsurface temperature and surface heat flow data exhibit major deviations from the axisymmetric approximation, exploratory three-dimensional calculations are performed to assess the effects of various mechanisms which might operate to produce such observed asymmetries. A three-dimensional model evolves from this iterative data synthesis and computer analysis which includes a hot fluid convective source distributed along a leaky fault radiating northward from the center of the hot spot and realistic variations in the reservoir formation properties

Depletion and recovery behavior of the Gladys McCall geopressured geothermal reservoir

Many sedimentary basins throughout the world contain sealed fault blocks in which the pore fluids are at higher pressures and temperatures than normal as a consequence of their depositional environment. The U.S. Department of Energy has drilled, completed, and tested four deep research wells in selected geopressured geothermal prospects in the Texas-Louisiana Gulf Coast region to evaluate the recoverability of the thermal, hydraulic, and chemical (methane) energy in this potential energy resource. The wells are expensive and the specific energy of the fluids is relatively small, but the total recoverable energy from a single well can be extremely large. Long-term testing of the Gladys McCall No. 1 research well, located in Cameron Parish, Louisiana, U.S.A., has defined an impressively large geopressured geothermal reservoir. In this paper an integrated analysis of the test data is presented, and a numerical model is constructed that matches the available data for the 6.5-year test history of the well