( ( Shale oil ) ( , ( ( in ( fossil ( fuel production ) ) ) ( , ( ( ( either ( a ( synthetic ( crude oil ) ) ) ) ( that ( is ( extracted ( from oil ) ) ) ) ) ( ( shale ( by ( ( ( means ( of pyrolysis ) ) or ) ( ( a ( ( naturally occurring ) ( crude oil ) ) ) ( that ( is ( ( extracted ( from ( underground ( shale deposits ) ) ) ) ( by ( means ( of ( fracking ( -LRB- ( ( hydraulic fracturing ) -RRB- ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) ) ) )
(ROOT (S (NP (NNP Shale) (NN oil)) (, ,) (PP (IN in) (NP (JJ fossil) (NN fuel) (NN production))) (, ,) (NP (NP (RB either) (DT a) (JJ synthetic) (JJ crude) (NN oil)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN extracted) (PP (IN from) (NP (NN oil)))))))) (VP (VBP shale) (PP (IN by) (NP (NP (NP (NNS means)) (PP (IN of) (NP (NNS pyrolysis)))) (CC or) (NP (NP (DT a) (ADJP (RB naturally) (VBG occurring)) (JJ crude) (NN oil)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN extracted) (PP (IN from) (NP (JJ underground) (NN shale) (NNS deposits))) (PP (IN by) (NP (NP (NNS means)) (PP (IN of) (NP (NP (NN fracking)) (PRN (-LRB- -LRB-) (NP (JJ hydraulic) (NN fracturing)) (-RRB- -RRB-)))))))))))))) (. .)))
Shale oil, in fossil fuel production, either a synthetic crude oil that is extracted from oil shale by means of pyrolysis or a naturally occurring crude oil that is extracted from underground shale deposits by means of fracking (hydraulic fracturing).
(ROOT (S (NP (NNP Fracking)) (VP (VBZ is) (NP (NP (DT another) (NN term)) (PP (IN for) (NP (JJ hydraulic) (NN fracturing))))) (. .)))