The 9th time we see the word Sheol in the Old Testament is in 2 Samuel 22:6.
This time, King David is singing a praise song to YHVH for deliverance from his enemies.
To put it in context, I'm including the whole sentence from v.5 to v.7
"When surround me the waves of death; the torrents of wickedness overwhelm me, the cords of Sheol are round about me; confront me the snares of death; in my distress I called on YHVH and to God."
The Hebrew here is a little choppy, so let's clean it up:
"When the waves of death surround me, the torrents of wickedness overwhelm me, the cords of Sheol are around me and the snares of death confront me, in my distress I called on YHVH and to God."
David was clearly alive when he wrote this, and had not been killed by Saul or any of his enemies, but surely believed that it was possible that he would be. The adjectives used - waves, torrents, cords, and snares - all describe a sense of being inexorably trapped. Waves and snares describe death, which pursue and eventually catch us all. "Torrents of wickedness" describe not only the people that tried to kill David, but also the lingering fear of death. Finally, cords of Sheol describe much the same as snares of death - it is not something we can escape.
No matter how we look at this one, Sheol means nothing more than the grave. You can't escape it. Only Jesus did!