ANADARKO		PETROLEUM		CORPORATION			1201 LAKE ROBBINS DRIVE, THE WOODLANDS, TEXAS 77380

			P.O. BOX 1330		HOUSTON, TEXAS 77251‐1330			U.S.A.			PH. (832)636‐1000

December	4,	2013	

Ms.	Kelly	Fortin		

U.S.	EPA	Region	4	

61	Forsyth	Street,	S.W.	

Atlanta,	GA	30303‐8960	

RE: Anadarko BlackHawk and BlackHornet OCS Air Permit Application for Drilling,

Exploration, and Maintenance Activities in the Eastern Gulf of Mexico

EPA’s Incompleteness Determination Letter Dated October 31, 2013

Response to Comment No. 11

11. Section	5.5	of	the	BACT	analysis	evaluated	controls	for	greenhouse	gases	(GHGs).		The	GHG	

analysis	for	the	diesel	fired	engines	omits	an	evaluation	of	energy	efficiency.	Please	address	the	

energy	efficiency	for	these	engines	in	the	analysis,	as	well	as,	the	efficiencies	of	newer	cleaner	

engines.	

Anadarko Response:				

The	energy	efficiency	of	an	engine	is	mainly	driven	by	an	inherent	engine	design	and	process	

controls	such	as	air/fuel	ratio	control,	combustion	temperature	control,	and	use	of	

manufacturer	recommended	operating	procedures	and	maintenance	schedule.		The	engines	

operated	with	too	much	excess	air	could	lead	to	inefficient	combustion,	and	additional	energy	

will	be	required	to	heat	the	excess	air.		Hence,	optimizing	air/fuel	ratio	minimizes	GHG	

emissions	by	efficiently	utilizing	the	fuel.		Turbochargers	typically	boost	cylinders’	temperature	

and	pressure,	which	result	in	higher	engine	output	and	increased	fuel	economy.			

Similarly,	maintaining	combustion	zone	temperature	at	a	recommended	range	and	following	

manufacturer	recommended	operating	procedures	and	maintenance	schedule	allows	an	engine	

to	run	in	a	fuel	efficient	manner.			Manufacturer	recommended	operating	procedures	typically	

include	documentation	of	operating	procedures,	training	to	operators,	and	proper	use	and	

supervision	of	the	inbuilt	control	systems.		Manufacturer	recommended	maintenance	schedule	

typically	includes	keeping	an	established	or	vendor‐issued	maintenance	schedule	and	keeping	

logs	of	maintenance	activities.			

To	meet	the	operational	requirements	of	the	proposed	project,	the	submitted	application	

included	several	diesel	fired	engines.		Based	on	the	power	rating,	whether	permanently	affixed	

on	the	drillship	or	temporarily	brought	on	board,	and	proposed	duration	of	use,	the	proposed	

engines	could	be	grouped	in	to	large	engines	(i.e.,	Drillship	Main	Engines),	emergency	engines	

(i.e.,	Emergency	Generator	and	Emergency	Air	Compressor),	third	party	EPA	Tier	2	certified	
Ms.	Fortin	

Page	2	of	3

engines,	and	job	specific	engines	(Third	Party	Well	Evaluation	Engines	and	Stimulation	Vessel	

Pump	Engines.)		Energy	efficiency	for	each	group	of	engines	and	the	proposed	BACT	is	discussed	

below.	

As	described	in	the	specification	sheet	in	Appendix	G‐1,	the	Drillship	Main	Engines	(DR‐ME‐1	to	

DR‐ME‐6)	are	designed	with	the	latest	fuel	efficient	design	techniques	such	as	optimized	

supercharging	with	Miller	Cycle,	Turbocharger	with	Aftercooler,	and	high	fuel	injection	pressure	

system.		The	combustion	chambers	in	these	engines	are	controlled	by	optimizing	the	piston	

bowl	shape	and	the	fuel	injection	valve	nozzle.		These	engines	are	also	equipped	with	a	

proprietary	Performance	Management	System,	which	results	in	efficient	use	of	fuel.		When	

compared	against	similar	sized	engines	installed	on	other	drillships	(e.g.,	Wartsila	18V32),	these	

engines	consume	comparable	(slightly	lower)	amount	of	fuel	for	per	unit	of	power	generated.			

Since	these	engines	are	manufactured	in	2012	using	the	most	recent	design	technology,	

Anadarko	believes	that	operating	these	engines	per	manufacturer	recommended	procedures	

and	following	manufacturer	recommended	operating	schedule	will	result	in	energy	efficient	

operations.		Anadarko	proposes	above	mentioned	inherent	engine	design	along	with	use	of	

manufacturer	recommended	operating	practices	and	maintenance	schedule	to	ensure	energy	

efficient	operation	of	these	engines.		Hence,	currently	proposed	BACT	in	Table	5‐22	of	the	

application	adequately	ensures	energy	efficient	operations	for	the	main	engines.	

The	Emergency	Generator	(DR‐GE‐01)	and	Emergency	Air	Compressor	(DR‐AC‐01)	operate	no	

more	than	100	hrs/year	for	readiness	testing	and	maintenance.			As	described	in	the	

specification	sheet	in	Appendix	G‐1,	the	Emergency	Generator	is	equipped	with	high	injection	

pressure	system	and	Turbocharger	with	Aftercooler,	which	result	in	higher	fuel	efficiency.		Since	

these	engines	operate	intermittently,	Anadarko	believes	that	operating	these	engines	per	

manufacturer	recommended	procedures	and	following	manufacturer	recommended	

maintenance	schedule	will	result	in	energy	efficient	operations.		Hence,	currently	proposed	

BACT	in	Table	5‐22	of	the	application	adequately	ensures	energy	efficient	operations	for	these	

engines.	

The	third	party	EPA	Tier	2	certified	engines	(DR‐TP‐01	to	DR‐TP‐11	and	DR‐TP‐17	to	DR‐TP‐21)	

are	temporarily	brought	on	board	to	perform	specific	operations.		In	order	to	demonstrate	

compliance	with	EPA	Tier	2	emission	standards,	these	engines	are	designed	to	optimize	

combustion	characteristics	such	as	air	to	fuel	ratio,	which	results	in	higher	fuel	efficiency.		

Although	cleaner	and	possibly	more	energy	efficient	engines	(e.g.,	EPA	Tier	3	and	EPA	Tier	4	

certified	engines)	are	available	to	replace	these	engines,	such	a	replacement	was	deemed	as	

technically	infeasible	based	on	the	limited	availability	of	such	cleaner	engines.		Refer	to	Section	

5.1.4	of	the	application	for	details.		Anadarko	proposes	engine	design	compliant	with	EPA	Tier	2	

emission	standards	along	with	use	of	manufacturer	recommended	operating	practices	and	

maintenance	schedule	to	ensure	energy	efficient	operation	of	these	engines.			Hence,	currently	

proposed	BACT	in	Table	5‐22	of	the	application	adequately	ensures	energy	efficient	operations	

for	these	engines.		

The	third	party	well	evaluation	engines	(DR‐TP‐12	to	DR‐TP‐16)	will	be	brought	onboard	to	

perform	‘check	shot’	operations.		As	explained	in	a	response	to	comment	no.	6,	no	cleaner	

engines	are	available	for	replacement	of	these	engines.		Moreover,	Anadarko	proposed	to	use	
Ms.	Fortin	

Page	3	of	3

each	of	these	engines	for	no	more	than	125	hours	in	a	year.		Since	these	engines	operate	

intermittently,	Anadarko	believes	that	operating	these	engines	per	manufacturer	recommended	

procedures	and	following	manufacturer	recommended	maintenance	schedule	will	result	in	

energy	efficient	operations.		Hence,	currently	proposed	BACT	in	Table	5‐22	of	the	application	

adequately	ensures	energy	efficient	operations	for	these	engines.	

Stimulation	Vessel	Pump	engines	(SV‐PE‐01	to	SV‐PE‐08)	will	be	used	for	specific	operations	

during	well	completion	activities.		As	specified	in	the	section	5.1.6	of	the	application,	

replacement	of	the	proposed	engines	with	the	cleaner	engines	was	deemed	as	technically	

infeasible	as	well	as	cost	prohibitive	since	such	a	replacement	will	essentially	require	redesign	

and	possible	recertification	of	the	stimulation	vessel.		Anadarko	believes	that	operating	these	

engines	per	manufacturer	recommended	procedures	and	following	manufacturer	recommended	

maintenance	schedule	will	result	in	energy	efficient	operations.		Hence,	currently	proposed	

BACT	in	Table	5‐22	of	the	application	adequately	ensures	energy	efficient	operations	for	these	

engines.	

Please	do	not	hesitate	to	contact	Ms.	Sara	Carlson	at	(832)	636‐1273	or	Mr.	Rahul	Pendse	at	(225)	346‐

4003	if	you	have	any	questions	or	require	additional	information	regarding	this	response.