| Kaarmise 719 borehole | Estonia | 58.3439, 22.3220 | 110 | 2 | 56 | 137 | 93 | |
| Kaasiksaare F-8 borehole | Estonia | 59.3596, 27.7058 | 389.2 | 6 | 3 | 2 | 2 | |
| Käesla 702 borehole | Estonia | 58.2828, 22.2108 | 100 | 4 | 20 | 0 | 0 | |
| Kaavi 568 borehole | Estonia | 57.9823, 22.1985 | 60.5 | 3 | 13 | 38 | 30 | |
| Kaavi 571 borehole | Estonia | 57.9836, 22.1765 | 40 | 9 | 12 | 50 | 165 | |
| Kabala borehole, Lääne-Virumaa | Estonia | 59.3560, 26.6041 | 321.7 | 6 | 1 | 2 | 2 | |
| Kaberla F-123 borehole | Estonia | 59.4900, 25.2547 | 239.6 | 5 | 0 | 21 | 21 | |
| Kabila F-316 borehole | Estonia | 59.2270, 24.4207 | 320.2 | 7 | 11 | 21 | 21 | |
| Kabuna K80 borehole | Estonia | 58.7317, 22.5492 | 39 | 0 | 0 | 0 | 0 | |
| Agama 658 borehole | Estonia | 58.3029, 22.0118 | 12 | 0 | 0 | 0 | 0 | |
| Kadila F-251 borehole | Estonia | 59.2283, 26.3191 | 520.5 | 9 | 3 | 114 | 202 | |
| Kaagvere 1 borehole | Estonia | 58.3499, 26.8890 | 499.4 | 40 | 736 | 432 | 400 | |
| Juminda 6 borehole | Estonia | 59.6414, 25.5049 | 181.4 | 7 | 0 | 13 | 13 | |
| Jaagarahu borehole | Estonia | 58.4071, 21.9632 | 61.56 | 6 | 90 | 95 | 107 | |
| Jaagarahu 24 borehole | Estonia | 58.4079, 21.9665 | | 0 | 0 | 0 | 0 | |
| Jaagarahu 699 borehole | Estonia | 58.4065, 21.9652 | 40.3 | 0 | 0 | 9 | 8 | |
| Jaagarahu 867 borehole | Estonia | 58.4014, 21.9822 | 120.1 | 0 | 0 | 0 | 0 | |
| Jaama 3 borehole | Estonia | 59.0482, 27.7394 | 383 | 16 | 91 | 278 | 354 | |
| Jaanika F-319 borehole | Estonia | 59.1534, 24.2942 | 320 | 2 | 0 | 12 | 11 | |
| Jakšiai 104 borehole | Lithuania | 55.2295, 23.6780 | | 4 | 57 | 70 | 66 | |
| Jalukse F-347 borehole | Estonia | 59.0142, 23.7850 | 309 | 3 | 1 | 13 | 9 | |
| Järise 689 borehole | Estonia | 58.4783, 22.4043 | 50.5 | 0 | 0 | 0 | 0 | |
| Järise 891 borehole | Estonia | 58.5001, 22.4292 | 80 | 0 | 0 | 0 | 0 | |
| Jašiunai 586 borehole | Lithuania | | | 1 | 0 | 14 | 11 | |
| Yashchera 8 borehole | Russia | 58.8955, 29.8185 | 236 | 0 | 0 | 62 | 55 | |
