| Kohtla 7 borehole | Estonia | 59.4N, 27.2E | 3 | 41 | 114 | 19 | |
| Kohtla-Järve borehole | Estonia | 59.4N, 27.3E | 0 | 0 | 0 | 0 | |
| Koigi 775 borehole | Estonia | 58.5N, 23.0E | 0 | 0 | 0 | 0 | |
| Kõiguste 833 borehole | Estonia | 58.4N, 23.0E | 5 | 7 | 39 | 82 | |
| Koikla 821 borehole | Estonia | 58.5N, 22.8E | 0 | 0 | 0 | 0 | |
| Koimla 560 borehole | Estonia | 58.2N, 22.1E | 0 | 0 | 0 | 0 | |
| Kõinastu 540 borehole | Estonia | 58.6N, 23.0E | 2 | 10 | 15 | 4 | |
| Koki 879 borehole | Estonia | 58.2N, 22.1E | 0 | 0 | 0 | 0 | |
| Koki 983 borehole | Estonia | 58.2N, 22.1E | 0 | 0 | 0 | 0 | |
| Koela F-348 borehole | Estonia | 59.0N, 23.7E | 3 | 0 | 41 | 49 | |
| Kybartai 33 borehole | Lithuania | | 0 | 2 | 0 | 0 | |
| Keila 117 borehole | Estonia | 59.3N, 24.4E | 10 | 0 | 56 | 31 | |
| Keila 30a borehole | Estonia | 59.3N, 24.4E | 1 | 0 | 1 | 0 | |
| Keila 8 borehole | Estonia | | 1 | 4 | 0 | 0 | |
| Keila quarry borehole | Estonia | 59.3N, 24.4E | 3 | 0 | 130 | 59 | |
| Kemba F-116 borehole | Estonia | 59.5N, 25.7E | 6 | 0 | 275 | 275 | |
| Kemeri-Loku 580 borehole | Estonia | 58.2N, 26.6E | 3 | 0 | 0 | 0 | |
| Kerema K170 borehole | Estonia | 58.9N, 23.0E | 0 | 1 | 0 | 0 | |
| Kerguse 743 borehole | Estonia | 58.3N, 22.4E | 0 | 0 | 0 | 0 | |
| Keri 258 borehole | Estonia | 58.3N, 26.5E | 1 | 0 | 16 | 36 | |
| Keskranna 798 borehole | Estonia | 58.4N, 22.1E | 1 | 0 | 0 | 0 | |
| Kestla 248 borehole | Estonia | 59.4N, 26.9E | 13 | 4 | 4 | 3 | |
| Ketrzyn IG 1 borehole, Poland | Poland | 54.1N, 21.4E | 5 | 98 | 46 | 46 | |
| Kioma 291 borehole | Estonia | 58.0N, 27.0E | 7 | 3 | 62 | 163 | |
| Kybartai 29 borehole | Lithuania | | 1 | 819 | 457 | 89 | |
