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_13 (surface VARCHAR, opponents VARCHAR)
### Question:
what is the surface when the opponents are louise field nathalie herreman?
### Answer:
SELECT surface FROM table_name_13 WHERE opponents = "louise field nathalie herreman"