Malcolm K. Strubhar

Coupling and recovering seismic detection sensors

A seismic system is placed in a predetermined orientation with respect to a surface of a formation, and a low viscosity substance is introduced between the sensor system and the surface of the formation. The substance has a composition formulated for stiffening in situ by increasing viscosity to provide a mechanical bond and an acoustical signal transmission coupling between the sensor system and the formation. After completion of the seismic operation, the stiffened substance is contacted with a stimulus for breaking the stiffened substance and thereby break the mechanical bond. Thereafter, the sensor system is recovered.

Multiple, Vertical Fractures From an Inclined Wellbore - A Field Experiment

A procedure is described in which multiple, vertical fractures are created from a single, directionally drilled well bore. The purpose is to increase fracture area over what can be achieved from a single vertical fracture initiated from a conventional vertical well bore. This will provide for more rapid and efficient drainage of a specific reservoir volume. A field experiment to test the feasibility of such a procedure was performed. A deviated well was drilled with the azimuth of deviation approx. normal to the azimuth of vertical hydrualically induced fractures, as measured by the borehole televiewer in other wells in the field. Deviation through the pay zone was about 52/sup 0/ from vertical. Fractures were initiated at 4 points within the pay, separated horizontally by about 45 ft. Drilling, completion, logging, fracturing, and producing were successfully achieved. Major conclusions based on the results of this test are (1) four separate, vertical hydraulic fractures were generated, as planned; and (2) productivity index of the well with 4 fractures was between 2 and 3 times that of a conventionally fractured well in this field. (11 refs.)

Fracturing results in diatomaceous earth formations, South Belridge Field, California

The company began fracturing diatomaceous earth zones in the San Joaquin Valley (CA) in 1976. Fracturing has proved an effective method of exploiting these previously noncommercial reservoirs. Nevertheless, productivity behavior is typified by high initial rates followed by rapid decline. Reasons for this decline have been evaluated and are discussed. Also discussed are laboratory experiments performed to determine an appropriate fracture design for this formation.

Simplified Performance Prediction Method for Vertically Fractured Gas Wells

A procedure is outlined for calculating the performance of a vertically fractured gas well contained within a square drainage area. Constant production rate and the constant well pressure cases are included. Because it is not a numerical simulator, calculations can be performed practically on small computers. Predicted comparisons with published reservoir simulator results and with actual production data from 2 massive hydraulically fractured wells were made. Agreement in both comparisons was very good. (14 refs.)