Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_19 (area_of_operation VARCHAR, services VARCHAR, years_of_operation VARCHAR)
### Question:
Where is the area of operation that had drilling during the year 1999?
### Answer:
SELECT area_of_operation FROM table_name_19 WHERE services = "drilling" AND years_of_operation = "1999"