РЕШЕНИЕ:
DECLARE @str VARCHAR(MAX) = '{"ABC":1,"ABC_DT":-1,"ABC_DBQty":0,"ABC_DSQty":0,"ABC_LMT":1,"ABC_DT":-1,"CTSD":"TEST","TE":23}'
,@posA INT = 0
,@posB INT = 0
,@res VARCHAR(MAX) = ''
SET @posA = PATINDEX('%"TE":%}', @str) +5;
SET @posB = CHARINDEX('}', @str, @posA+1);
SET @res = SUBSTRING (@str ,@posA, @posB-@posA )
SELECT @res AS 'STR_res', CAST(@res AS INT) AS 'INT_res'