RESCUE AND PRESERVATION OF A LARGE COLLECTION OF OIL AND GAS WELL DRILL CUTTINGS AND ASSOCIATED PAPER SCOUT REPORTS

The Michigan Geologic Survey preserves geological samples and data, making them readily accessible for research and education. Recently we rescued a large collection of historical drill cuttings from sedimentary formations throughout Michigan’s Lower Peninsula. They were acquired during early oil and gas drilling from the late 1920’s-1950’s. The collection consists of samples from more than 5000 individual wells, stored on over 15,000 trays, representing nearly 8 million drilled feet of geological strata.

All the samples are contained in fragile glass vials placed loosely on cardboard trays stacked in large paper boxes. The boxes had sustained water damage and deterioration from poor storage conditions. Because the boxes had been moved several times, many of the vials had rolled out of the trays and there was little remaining order. Often the paper labels on vials, identifying the well and sample footage, were only loosely affixed. Some of the vials were cracked and a few had broken. Even so, most of the sample material remained in the vials. The trays and vials were generally labeled only by the company’s county and well reference number.

To build a useful collection database, we identified each well by permit number, relying on information from the vials and from a set of company paper records called “scout tickets”. Complete inventories with detailed sample footages and relevant location information have been prepared and metadata created.

To preserve these fragile samples, we repaired or replaced damaged glass vials and storage trays and boxes, and taped loose labels to vials, taking care to retain original information. We organized vials by depth within each well and taped the vials to trays. We made these samples accessible and known to stakeholders by uploading inventories to the National Digital Catalogue through the National Geological and Geophysical Data Preservation Program and to our Survey Web pages.

Cuttings are valuable rock samples that must be preserved because they often are the only physical samples from many older wells. By using new technologies such as geochemical sampling and high-resolution microscopy, these old samples can reveal new data, providing insights into reservoir properties and thermal maturation.