On the prospect of creating wellbore gravimeters based on film accelerometers
- 1 — G.V. Plekhanov Saint Petersburg Mining University
- 2 — G.V. Plekhanov Saint Petersburg Mining University
- 3 — G.V. Plekhanov Saint Petersburg Mining University
Abstract
Development of downhole gravimeter on modern highly sensitive elements on the basis of film accelerometers, providing high reliability of operation, for solving various geological problems: study of interwell space outside the well and below the well bottom to identify ore bodies; detection of oil targets and washed zones of oil fields in the late stage of development; control of gas injection and consumption in underground gas storages, etc. is proposed. Proceeding from real listed problems, the necessity and opportunity of creation of a downhole gravimeter-gradientmeter with sensitivity (0.05-0.1) - 10” 5 m/sec 2 has been scientifically proved. Such sensitivity is provided at the expense of high sensitivity of sensors, computer introduction of temperature corrections, consideration of device position in a borehole. There are theoretical calculations of possible gravity anomalies and its gradients over objects of regular geometric shape: a sphere, a vertical cylinder, a horizontal formation of finite thickness. The results of the calculations are compared with field observations during the exploration of copper and sulfide deposits and oil and gas fields. Experimental studies of the main units of the borehole gravimeter equipment were performed and their laboratory and bench tests were carried out, which confirmed the correctness of theoretical calculations.