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	analysi s	evaluated	controls	for	greenho use	gases	(GHGs).		The	GHG analysis	for	the	diesel	fired	en gines	omits	an	e valuation	of	en ergy	efficiency.	Pl ease	address	the energy	efficiency	for	these	engin es	in	the	analysis,	as	well	as ,	the	efficiencies of	newer	cleaner engines.

Anadarko Response :

The	energy	efficiency	o f	an	engine	is	mainly	driven	by	an	inher ent	engine	design	and	process controls	such	as	air/fuel	ratio control,	combustion	temperature control,	and	use	of manufacturer	recommended	operati ng	procedures	and	maintenance	s chedule.		The	engines operated	with	too	much	excess	air could	lead	to	inefficient	com bustion,	and	additional	energy will	be	required	to	h eat	the	excess	air.		H ence,	optimizing	air /fuel	ratio	minimizes	GHG emissions	by	efficientl y	utilizing	the	fuel .		Turbochargers	typ ically	boost	cylinders’	temperature and	pressure,	which	result	in	hig her	engine	output	and	increase d	fuel	economy.

Similarly,	maintaining	combustion	zone	temperature	at	a	recomme nded	range	and	following manufacturer	recommended	operati ng	procedures	and	maintenance	s chedule	allows	an	engine
to	run	in	a	fuel	efficient	mann er.			Manufacturer	recommended	o perating	procedures	typically include	documentation	of	operati ng	procedures,	training	to	oper ators,	and	proper	use	and supervision	of	the	i nbuilt	control	systems.		Manufacturer	recom mended	maintenance	schedule typically	includes	keeping	an	est ablished	or	vendor‐issued	main tenance	schedule	and	keeping logs	of	maintenance	activities.

To	meet	the	operational	requiremen ts	of	the	proposed	project,	t he	submitted	application included	several	diesel	fired	eng ines.		Based	on	the	power	rati ng,	whether	perm anently	affixed on	the	drillship	or	temporarily	brought	on	board,	and	proposed duration	of	use,	the	proposed engines	could	be	grouped	in	to	l arge	engines	(i.e.,	Drillship	M ain	Engines),	em ergency	engines (i.e.,	Emergency	Generator	and	Em ergency	Air	Compressor),	third party	EPA	Tier	2	certifiedMs.	Fortin Page 2 of 3

engines,	and	job	specific	engine s	(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	specificatio n	sheet	in	Appendix	G‐1,	the	Dr illship	Main	Engines	(DR‐ME‐1	to DR‐ME‐6)	are	designed	with	the	la test	fuel	efficient	design	tec hniques	such	as	optimized supercharging	with	Miller	Cycl e,	Turbocharger	with	Aftercooler, and	high	fuel	injection	pressure system.		The	combustion	chambers in	these	engines	are	controlle d	by	optimizing	the	piston bowl	shape	and	the	fuel	injectio n	valve	nozzle.		These	engines are	also	equipped	with	a proprietary	Performance	Manageme nt	System,	which	results	in	eff icient	use	of	fuel.		When compared	against	similar	sized	e ngines	installed	on	other	drill ships	(e.g.,	Wartsi la	18V32),	these engines	consume	comparable	(slig htly	lower)	amount	of	fuel	for per	unit	of	power	generated.

Since	these	engines are	manufactured	in	2012	using	the	most	rec ent	design	technology, Anadarko	believes	that	operating these	engines	per	manufacturer recommended	procedures and	following	manufacturer	recomme nded	operating	schedule	will result	in	energy	efficient operations.		Anadarko	proposes	ab ove	mentioned	inherent	engine design	along	with	use	of manufacturer	recommended	operati ng	practices	and	maintenance	sc hedule	to	ensure	energy efficient	operation	of	these	en gines.		Hence,	currently	propose d	BACT	in	Table	5‐22	of	the application	adequately	ensures	e nergy	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	readi ness	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	effi ciency.		Since these	engines	operate	intermittent ly,	Anadarko	believes	that	op erating	these	engines	per manufacturer	recommended	procedu res	and	followin g	manufacturer recommended
maintenance	schedule	will	result in	energy	efficient	operations .		Hence,	currently	proposed BACT	in	Table	5‐22	of	the	applicat ion	adequately	ensures	energy efficient	operati ons	for	these engines.

The	third	party	EPA	Tier	2	certif ied	engines	(DR‐TP‐01	to	DR‐TP ‐11	and	DR‐TP‐17	to	DR‐TP‐21) are	temporarily	brough t	on	board	to	perform	specific	operations .		In	order	to	demonstrate compliance	with	EPA	Ti er	2	emission	standar ds,	these	engines	ar e	designed	to	optimize
combustion	characteristics	such	a s	air	to	fuel	ra tio,	which	res ults	in	higher	fu el	efficiency. Although	cleaner	and possibly	more	energy	e fficient	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	t he	limited	availability	of	suc h	cleaner	engines. Refer	to	Section 5.1.4	of	the	application	for	detail s.		Anadarko	proposes	engine design	compliant	with	EPA	Tier	2 emission	standards	along	with use	of	manufacturer	recommended	o perating	practices	and
maintenance	schedule	to	ensure energy	efficient	operation	of	th ese	engines.			Hence,	currently proposed	BACT	in	Table	5‐22	of	t he	application	adequately	ensur es	energy	efficient	operations for	these	engines.

The	third	party	well	e valuation	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.		Moreov er,	Anadarko	proposed	to	useMs.	Fortin Page 3 of 3

each	of	these	engines for	no	more	than	125	hours	in	a	year.		Si nce	these	engines	operate intermittently,	Anadarko	believe s	that	operating	these	engines per	manufacturer	recommended procedures	and	following	manufac turer	recommended	maintenance	s chedule	will	result	in energy	efficient	operations.		Hen ce,	currently	proposed	BACT	in Table	5‐22	of	the	application adequately	ensures	energy	effici ent	operations	fo r	these	engine s.

Stimulation	Vessel	Pump	engines (SV‐PE‐01	to	SV‐PE‐08)	will	be used	for	specific	operations during	well	completion	activitie s.		As	specified	in	the	section 5.1.6	of	the	application, replacement	of	the	proposed	engin es	with	the	cleaner	engines	wa s	deemed	as	technically
infeasible	as	well	as cost	prohibitive	since	such	a	replacement will	essentially require	redesign and	possible	recertification	of the	stimulation	vessel.		Anadar ko	believes	that	operating	these engines	per	manufacturer	recomme nded	procedures and	following	m anufacturer	recommended
maintenance	schedule	will	result in	energy	efficient	operations .		Hence,	currently	proposed BACT	in	Table	5‐22	of	the	applicat ion	adequately	ensures	energy efficient	operati ons	for	these engines.

Please	do	not	hesitate	to	contac t	Ms.	Sara	Carlson	at	(832)	636 ‐1273	or	Mr.	Rahul	Pendse	at	(225)	346‐ 4003	if	you	have	any	questions	or require	addition al	informatio n	regarding	this	response.