Suspended Wells	12 Months Ended
Dec. 31, 2019
Suspended Wells [Abstract]
Suspended Wells	Note 8—Suspended Wells and Other Exploration Expenses The following table reflects the net changes in suspended exploratory well costs during 2019, 2018 and 2017: Millions of Dollars 2019 2018 2017 Beginning balance at January 1 $ 856 853 1,063 Additions pending the determination of proved reserves 239 140 118 Reclassifications to proved properties (11) (37) (66) Sales of suspended wells (54) (93) - Charged to dry hole expense (10) (7) (262) Ending balance at December 31 $ 1,020 * 856 853 The following table provides an aging of suspended well balances at December 31: Millions of Dollars 2019 2018 2017 Exploratory well costs capitalized for a period of one year or less $ 206 145 67 Exploratory well costs capitalized for a period greater than one year 814 711 786 Ending balance $ 1,020 * 856 853 Number of projects with exploratory well costs capitalized for a period greater than one year 23 24 23 The following table provides a further aging of those exploratory well costs that have been capitalized for more than one year since the completion of drilling as of December 31, 2019: Millions of Dollars Suspended Since Total 2016–2018 2013–2015 2004–2012 Greater Poseidon—Australia (2)(3) 177 - 157 20 NPRA—Alaska (1) 149 111 38 - Barossa/Caldita—Australia (2)(3) 136 59 - 77 Surmont—Canada (1) 118 6 55 57 Middle Magdalena Basin—Colombia (1) 68 - 68 - Narwhal Trend—Alaska (1) 52 52 - - Kamunsu East—Malaysia (2) 19 - 19 - NC 98—Libya (2) 15 - 11 4 WL4-00—Malaysia (2) 17 17 - - Other of $10 million or less each (1)(2) 63 20 26 17 Total $ 814 265 374 175 (1)Additional appraisal wells planned. (2)Appraisal drilling complete; costs being incurred to assess development. (3)Assets held for sale as of December 31, 2019. Other Exploration Expenses In February 2017, we reached a settlement agreement on our contract for the Athena drilling rig, initially secured for our four-well commitment program in Angola. As a result of the cancellation, we recognized a before-tax charge of $ 43 million net in the first quarter of 2017. These charges are included in the “Exploration expenses” line on our consolidated income statement and in our Other International segment in 2017. In 2019, we recorded before-tax dry hole expenses of $ 111 million due to our decision to discontinue exploration activities in the Central Louisiana Austin Chalk trend. These charges are included in our Lower 48 segment and in the “Exploration expenses” line on our consolidated income statement. See Note 9— Impairments for additional information on our decision to discontinue these exploration activities.

Note 8—Suspended Wells and Other Exploration Expenses

The following table reflects the net changes in suspended

exploratory well costs during 2019, 2018 and 2017:

Millions of Dollars

2019

2018

2017

Beginning balance at January 1

856

853

1,063

Additions pending the determination of proved reserves

239

140

118

Reclassifications to proved properties

(11)

(37)

(66)

Sales of suspended wells

(54)

(93)

Charged to dry hole expense

(10)

(7)

(262)

Ending balance at December 31

1,020

856

853

The following table provides an aging of suspended

well balances at December 31:

Millions of Dollars

2019

2018

2017

Exploratory well costs capitalized for a period

of one year or less

206

145

Exploratory well costs capitalized for a period

greater than one year

814

711

786

Ending balance

1,020

856

853

Number of projects with exploratory well costs

capitalized for a

period greater than one year

The following table provides a further aging of

those exploratory well costs that have

been capitalized for more

than one year since the completion of drilling

as of December 31, 2019:

Millions of Dollars

Suspended Since

Total

2016–2018

2013–2015

2004–2012

Greater Poseidon—Australia

(2)(3)

177

157

NPRA—Alaska

(1)

149

111

Barossa/Caldita—Australia

(2)(3)

136

Surmont—Canada

(1)

118

Middle Magdalena Basin—Colombia

(1)

Narwhal Trend—Alaska

(1)

Kamunsu East—Malaysia

(2)

NC 98—Libya

(2)

WL4-00—Malaysia

(2)

Other of $10 million or less each

(1)(2)

Total

814

265

374

175

(1)Additional appraisal wells planned.

(2)Appraisal drilling complete; costs being incurred to assess development.

(3)Assets held for sale as of December 31, 2019.

Other Exploration Expenses

In February 2017, we reached a settlement

agreement on our contract for the Athena drilling

rig, initially

secured for our four-well commitment program

in Angola.

As a result of the cancellation, we recognized

before-tax charge of $

million net in the first quarter of 2017.

These charges are included in the

“Exploration expenses” line on our consolidated income

statement and in our Other International segment

2017.

In 2019, we recorded before-tax dry hole expenses

of $

111

million due to our decision to discontinue

exploration activities in the Central Louisiana Austin

Chalk trend.

These charges are included in our Lower 48

segment and in the “Exploration expenses” line

on our consolidated income statement.

See Note 9—

Impairments for additional information on our

decision to discontinue these exploration activities.