see properties – proved reserves under part i , item 2 ; selected financial data under part ii , item 6 and financial statements and supplementary data – note 20 – supplemental oil and gas disclosures under part ii , item 8 in this form 10-k for additional information on our proved reserves . our drilling efforts in recent years have included the deepwater of the gulf of mexico . production from our deepwater fields represented 41 % , 42 % , and 46 % of our total production for the years 2018 , 2017 , and 2016 , respectively . one of our larger deepwater fields is the big bend field , which commenced production in late 2015. over 90 % of our reserves in this field are composed of oil and ngls on a boe basis . as of december 31 , 2018 , the big bend field was in our top ten fields based on reserves , net to our interest , on a boe basis . 53 to provide additional financial flexibility , we created the jv drilling program during 2018 and initiated drilling on several of the projects . the jv drilling program enables w & t to receive returns on its investment on a promoted basis and enables private investors to participate in 14 drilling projects . it also allows more projects to be taken on which leverages our capital expenditures and diversifies our risk . during 2018 , there were four wells in the jv drilling program that came on production . in addition , as of december 31 , 2018 , one well was being drilled and one well was in the completion stage . the current plan is to complete the 14 projects within a three-year period , but is subject to change as needed with any required approval of the other investors . see financial statements and supplementary data – note 4 – joint venture drilling program under part ii , item 8 in this form 10-k for additional information on the jv drilling program . in october 2018 , we entered into a series of transactions to effect a refinancing of substantially all of our outstanding indebtedness . at that time , we issued $ 625.0 million of 9.75 % senior second lien notes , which were issued at par with an interest rate of 9.75 % per annum that matures on november 1 , 2023. concurrently , we renewed our credit facility by entering into the credit agreement , which matures on october 18 , 2022 and increased the borrowing base from $ 150.0 million to $ 250.0 million . the borrowing base is subject to scheduled semi-annual redeterminations to occur on or before may 15 and november 14 each calendar year , and certain additional redeterminations that may be requested at the discretion of either the lenders or the company . funds from the senior second lien notes , cash on hand and borrowings under the credit agreement were used to repurchase and retire , repay or redeem all of our previously outstanding secured senior notes and secured term loans . the refinancing transaction reduced our debt levels , extended the maturities for our fixed rate debt and provides extended liquidity under the credit agreement through october 2022. see financial statements and supplementary data – note 2 – long-term debt under part ii , item 8 in this form 10-k for a full description of the transaction and the new debt instruments . our financial condition , cash flow and results of operations are significantly affected by the volume of our oil , ngls and natural gas production and the prices that we receive for such production . our production volumes for 2018 were comprised of approximately 50 % oil and condensate , 10 % ngls and 40 % natural gas , determined using the energy-equivalent ratio of six mcf of natural gas to one barrel of crude oil , condensate or ngls . the energy-equivalent ratio does not assume price equivalency , and the energy-equivalent prices per mcfe for crude oil , ngls and natural gas may differ significantly . for 2018 , our combined total production of oil , ngls and natural gas was 8.5 % below 2017 , primarily due to natural production declines , partially offset by production from wells drilled and completed during 2018 and 2017 and from acquisitions . our realized sales prices received for our crude oil , ngls and natural gas production are affected by not only domestic production activities and political issues , but more importantly , international events , including both geopolitical and economic events . during 2018 , crude oil and ngl average realized prices were significantly above 2017 realized prices , increasing 36.3 % and 21.6 % , respectively . selected issues and data points related to crude oil , ngls and natural gas markets are described below . as reported by the u.s. energy information administration ( “ eia ” ) in their short-term energy outlook issued in january 2019 ( “ steo ” ) , worldwide production of petroleum and other liquids was estimated to have increased by 2.8 % in 2018 over the prior year , which was higher than the year-over-year production growth experienced from the last two years of 0.5 % for 2017 and 1.5 % for 2016. the increases in production for 2018 were primary from increases in the u.s. consumption for 2018 increased 1.5 % over 2017 and was lower than production , resulting in inventory builds for 2018. the eia forecasts worldwide production of petroleum and other liquids year-over-year increases for 2019 and 2020 to be 1.4 % and 1.7 % , respectively . the increase is due primarily to increases in production in the u.s. and brazil . story_separator_special_tag the ngls revenue increase was attributable to a 21.6 % increase in the average realized sales price to $ 28.40 per barrel in 2018 from $ 23.35 per barrel in 2017 , partially offset by a decrease of 5.4 % in sales volumes . the decrease in natural gas revenue was attributable to a 13.0 % decrease in sales volumes , partially offset by a 5.1 % increase in the average realized natural gas sales price to $ 3.11 per mcf in 2018 from $ 2.96 per mcf in 2017. overall , prices increased 30.8 % on a per boe basis and production declined 8.5 % on a per boe per day basis . the largest production increases for 2018 compared to 2017 were from our newly acquired interest in the heidelberg field and our ship shoal 300 field . revenue and production was adjusted for royalty relief on two of our deepwater fields related to their 2017 and 2016 production and realized prices which is recognized in the subsequent year . this royalty relief impact to revenues during 2018 and 2017 was $ 1.0 million and $ 5.0 million , respectively . offsetting were production decreases primarily due to natural production declines and production deferrals . production for 2018 was also negatively impacted by maintenance , well issues and pipeline outages that collectively resulted in deferred production of 1.6 mmboe , which was approximately the same amount as in 2017 . 57 revenues from oil and liquids as a percent of our total revenues were 82.0 % for 2018 compared to 76.4 % for 2017. ngls realized sales prices as a percent of crude oil realized prices decreased to 43.3 % for 2018 compared to 48.5 % for 2017. lease operating expenses . lease operating expenses , which include base lease operating expenses , insurance , workovers , and facilities maintenance , increased $ 9.5 million , or 6.6 % , to $ 153.3 million in 2018 compared to $ 143.7 million in 2017. the heidelberg field acquisition accounted for approximately half of the lease operating expense increase . on a per boe basis , lease operating expenses increased to $ 11.50 per boe during 2018 compared to $ 9.86 per boe during 2017. on a component basis , base lease operating expenses increased $ 5.1 million and insurance premiums increased $ 2.2 million and workover expenses increased $ 2.3 million , partially offset by facilities maintenance decreases of $ 0.1 million . base lease operating expenses increased primarily due the addition of the heidelberg field , lower product handling and operating charges to an outside party at our matterhorn field and higher incentive compensation expenses . the insurance premium increase is primarily due to our insurance policies related to named windstorms , which had expanded coverage in 2018 compared to the 2017 period , as named windstorm coverage was limited to just our mahogany field in the first half of 2017. the increase in workover expenses is primarily attributable to additional projects at our mahogany field compared to the prior year to increase production . production taxes . production taxes were $ 1.8 million , approximately the same as in 2017. most of our production is from federal waters where no production taxes are imposed . our fairway field , which is in state waters , is subject to production taxes . gathering and transportation costs . gathering and transportation costs increased to $ 22.4 million , or 9.5 % , in 2018 compared to $ 20.4 million in 2017 primarily related to the heidelberg field , where we are required to pay additional amounts if throughputs are below minimums quantities and were partially offset by lower expenses from lower production volumes . depreciation , depletion , amortization and accretion . dd & a , which includes accretion for aro , increased to $ 11.24 per boe in 2018 from $ 10.68 per boe in 2017. on a nominal basis , dd & a decreased to $ 149.9 million ( 3.7 % ) in 2018 from $ 155.7 million in 2017. dd & a on a nominal basis decreased primarily due to lower production , partially offset by an increase in the dd & a rate . factors affecting the dd & a rate are capital expenditures , changes in future development costs on remaining reserves and changes in proved reserve volumes . general and administrative expenses ( “ g & a ” ) . for 2018 , g & a expenses of $ 60.1 million were essentially at the same level as in 2017. we experienced reductions in legal settlements , fines and contract labor , offset by increases for settlements related to the departure of certain executives , increases in medical claims and a buyout of an office lease . g & a on a per boe basis was $ 4.51 boe for 2018 compared to $ 4.10 boe for 2017. see financial statements and supplementary data – note 11 – share-based awards and cash-based awards under part ii , item 8 in this form 10-k for additional information . derivative gain . for 2018 , a $ 53.8 million derivative gain was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil during the second quarter of 2018 relating to a portion of our 2018 estimated production , which expired in december 2018. in the fourth quarter of 2018 , we entered into additional derivative contracts for crude oil and natural gas , which consists primarily of crude oil contracts with a term of 18 months . for 2017 , a $ 4.2 million derivative gain was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil and natural gas during the first quarter of 2017 relating to a portion of our 2017 estimated production and there were no open contracts as of december 31 , 2017. see financial

gain on exchange of debt . during 2018 , the refinancing transaction resulted in a gain of $ 47.1 million for 2018. during 2017 , a net gain of $ 7.8 million was recognized primarily as a result of paying interest in cash on certain debt instruments that had the option of paying-in-kind ( “ pik ” ) or in cash . see financial statements and supplementary data - note 2 – long-term debt under part ii , item 8 in this form 10-k for additional information . other ( income ) expense , net . during 2018 and 2017 , other ( income ) expense , net , was $ 3.9 million of net income and $ 5.1 million of net expense , respectively . for 2018 , the amount consists of credits related to the de-recognition of certain liabilities that had exceeded the statute of limitations , partially offset by expenses related to the amortization of the brokerage fee paid in connection with the jv drilling program . for 2017 , the amount consists primarily of expense items related to the apache lawsuit of $ 6.3 million , partially offset by loss-of-use reimbursements from a third-party for damages incurred at one of our platforms of $ 1.1 million . see financial statements and supplementary data - note 18 – contingencies under part ii , item 8 in this form 10-k for additional information . income tax benefit . our income tax expense for 2018 was $ 0.5 million and our income tax benefit for 2017 was $ 12.6 million . for 2018 , immaterial deferred tax expense was recorded due to dollar-for-dollar offsets by our valuation allowance . the income tax benefit for 2017 was primarily attributable to claims made pursuant to internal revenue code ( “ irc ” ) section 172 ( f ) , ( related to rules for “ specified liability losses ” ) which permit certain platform dismantlement , well abandonment and site clearance costs to be carried back 10 years .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```gain on exchange of debt . during 2018 , the refinancing transaction resulted in a gain of $ 47.1 million for 2018. during 2017 , a net gain of $ 7.8 million was recognized primarily as a result of paying interest in cash on certain debt instruments that had the option of paying-in-kind ( “ pik ” ) or in cash . see financial statements and supplementary data - note 2 – long-term debt under part ii , item 8 in this form 10-k for additional information . other ( income ) expense , net . during 2018 and 2017 , other ( income ) expense , net , was $ 3.9 million of net income and $ 5.1 million of net expense , respectively . for 2018 , the amount consists of credits related to the de-recognition of certain liabilities that had exceeded the statute of limitations , partially offset by expenses related to the amortization of the brokerage fee paid in connection with the jv drilling program . for 2017 , the amount consists primarily of expense items related to the apache lawsuit of $ 6.3 million , partially offset by loss-of-use reimbursements from a third-party for damages incurred at one of our platforms of $ 1.1 million . see financial statements and supplementary data - note 18 – contingencies under part ii , item 8 in this form 10-k for additional information . income tax benefit . our income tax expense for 2018 was $ 0.5 million and our income tax benefit for 2017 was $ 12.6 million . for 2018 , immaterial deferred tax expense was recorded due to dollar-for-dollar offsets by our valuation allowance . the income tax benefit for 2017 was primarily attributable to claims made pursuant to internal revenue code ( “ irc ” ) section 172 ( f ) , ( related to rules for “ specified liability losses ” ) which permit certain platform dismantlement , well abandonment and site clearance costs to be carried back 10 years .
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 Suspicious Activity Report : see properties – proved reserves under part i , item 2 ; selected financial data under part ii , item 6 and financial statements and supplementary data – note 20 – supplemental oil and gas disclosures under part ii , item 8 in this form 10-k for additional information on our proved reserves . our drilling efforts in recent years have included the deepwater of the gulf of mexico . production from our deepwater fields represented 41 % , 42 % , and 46 % of our total production for the years 2018 , 2017 , and 2016 , respectively . one of our larger deepwater fields is the big bend field , which commenced production in late 2015. over 90 % of our reserves in this field are composed of oil and ngls on a boe basis . as of december 31 , 2018 , the big bend field was in our top ten fields based on reserves , net to our interest , on a boe basis . 53 to provide additional financial flexibility , we created the jv drilling program during 2018 and initiated drilling on several of the projects . the jv drilling program enables w & t to receive returns on its investment on a promoted basis and enables private investors to participate in 14 drilling projects . it also allows more projects to be taken on which leverages our capital expenditures and diversifies our risk . during 2018 , there were four wells in the jv drilling program that came on production . in addition , as of december 31 , 2018 , one well was being drilled and one well was in the completion stage . the current plan is to complete the 14 projects within a three-year period , but is subject to change as needed with any required approval of the other investors . see financial statements and supplementary data – note 4 – joint venture drilling program under part ii , item 8 in this form 10-k for additional information on the jv drilling program . in october 2018 , we entered into a series of transactions to effect a refinancing of substantially all of our outstanding indebtedness . at that time , we issued $ 625.0 million of 9.75 % senior second lien notes , which were issued at par with an interest rate of 9.75 % per annum that matures on november 1 , 2023. concurrently , we renewed our credit facility by entering into the credit agreement , which matures on october 18 , 2022 and increased the borrowing base from $ 150.0 million to $ 250.0 million . the borrowing base is subject to scheduled semi-annual redeterminations to occur on or before may 15 and november 14 each calendar year , and certain additional redeterminations that may be requested at the discretion of either the lenders or the company . funds from the senior second lien notes , cash on hand and borrowings under the credit agreement were used to repurchase and retire , repay or redeem all of our previously outstanding secured senior notes and secured term loans . the refinancing transaction reduced our debt levels , extended the maturities for our fixed rate debt and provides extended liquidity under the credit agreement through october 2022. see financial statements and supplementary data – note 2 – long-term debt under part ii , item 8 in this form 10-k for a full description of the transaction and the new debt instruments . our financial condition , cash flow and results of operations are significantly affected by the volume of our oil , ngls and natural gas production and the prices that we receive for such production . our production volumes for 2018 were comprised of approximately 50 % oil and condensate , 10 % ngls and 40 % natural gas , determined using the energy-equivalent ratio of six mcf of natural gas to one barrel of crude oil , condensate or ngls . the energy-equivalent ratio does not assume price equivalency , and the energy-equivalent prices per mcfe for crude oil , ngls and natural gas may differ significantly . for 2018 , our combined total production of oil , ngls and natural gas was 8.5 % below 2017 , primarily due to natural production declines , partially offset by production from wells drilled and completed during 2018 and 2017 and from acquisitions . our realized sales prices received for our crude oil , ngls and natural gas production are affected by not only domestic production activities and political issues , but more importantly , international events , including both geopolitical and economic events . during 2018 , crude oil and ngl average realized prices were significantly above 2017 realized prices , increasing 36.3 % and 21.6 % , respectively . selected issues and data points related to crude oil , ngls and natural gas markets are described below . as reported by the u.s. energy information administration ( “ eia ” ) in their short-term energy outlook issued in january 2019 ( “ steo ” ) , worldwide production of petroleum and other liquids was estimated to have increased by 2.8 % in 2018 over the prior year , which was higher than the year-over-year production growth experienced from the last two years of 0.5 % for 2017 and 1.5 % for 2016. the increases in production for 2018 were primary from increases in the u.s. consumption for 2018 increased 1.5 % over 2017 and was lower than production , resulting in inventory builds for 2018. the eia forecasts worldwide production of petroleum and other liquids year-over-year increases for 2019 and 2020 to be 1.4 % and 1.7 % , respectively . the increase is due primarily to increases in production in the u.s. and brazil . story_separator_special_tag the ngls revenue increase was attributable to a 21.6 % increase in the average realized sales price to $ 28.40 per barrel in 2018 from $ 23.35 per barrel in 2017 , partially offset by a decrease of 5.4 % in sales volumes . the decrease in natural gas revenue was attributable to a 13.0 % decrease in sales volumes , partially offset by a 5.1 % increase in the average realized natural gas sales price to $ 3.11 per mcf in 2018 from $ 2.96 per mcf in 2017. overall , prices increased 30.8 % on a per boe basis and production declined 8.5 % on a per boe per day basis . the largest production increases for 2018 compared to 2017 were from our newly acquired interest in the heidelberg field and our ship shoal 300 field . revenue and production was adjusted for royalty relief on two of our deepwater fields related to their 2017 and 2016 production and realized prices which is recognized in the subsequent year . this royalty relief impact to revenues during 2018 and 2017 was $ 1.0 million and $ 5.0 million , respectively . offsetting were production decreases primarily due to natural production declines and production deferrals . production for 2018 was also negatively impacted by maintenance , well issues and pipeline outages that collectively resulted in deferred production of 1.6 mmboe , which was approximately the same amount as in 2017 . 57 revenues from oil and liquids as a percent of our total revenues were 82.0 % for 2018 compared to 76.4 % for 2017. ngls realized sales prices as a percent of crude oil realized prices decreased to 43.3 % for 2018 compared to 48.5 % for 2017. lease operating expenses . lease operating expenses , which include base lease operating expenses , insurance , workovers , and facilities maintenance , increased $ 9.5 million , or 6.6 % , to $ 153.3 million in 2018 compared to $ 143.7 million in 2017. the heidelberg field acquisition accounted for approximately half of the lease operating expense increase . on a per boe basis , lease operating expenses increased to $ 11.50 per boe during 2018 compared to $ 9.86 per boe during 2017. on a component basis , base lease operating expenses increased $ 5.1 million and insurance premiums increased $ 2.2 million and workover expenses increased $ 2.3 million , partially offset by facilities maintenance decreases of $ 0.1 million . base lease operating expenses increased primarily due the addition of the heidelberg field , lower product handling and operating charges to an outside party at our matterhorn field and higher incentive compensation expenses . the insurance premium increase is primarily due to our insurance policies related to named windstorms , which had expanded coverage in 2018 compared to the 2017 period , as named windstorm coverage was limited to just our mahogany field in the first half of 2017. the increase in workover expenses is primarily attributable to additional projects at our mahogany field compared to the prior year to increase production . production taxes . production taxes were $ 1.8 million , approximately the same as in 2017. most of our production is from federal waters where no production taxes are imposed . our fairway field , which is in state waters , is subject to production taxes . gathering and transportation costs . gathering and transportation costs increased to $ 22.4 million , or 9.5 % , in 2018 compared to $ 20.4 million in 2017 primarily related to the heidelberg field , where we are required to pay additional amounts if throughputs are below minimums quantities and were partially offset by lower expenses from lower production volumes . depreciation , depletion , amortization and accretion . dd & a , which includes accretion for aro , increased to $ 11.24 per boe in 2018 from $ 10.68 per boe in 2017. on a nominal basis , dd & a decreased to $ 149.9 million ( 3.7 % ) in 2018 from $ 155.7 million in 2017. dd & a on a nominal basis decreased primarily due to lower production , partially offset by an increase in the dd & a rate . factors affecting the dd & a rate are capital expenditures , changes in future development costs on remaining reserves and changes in proved reserve volumes . general and administrative expenses ( “ g & a ” ) . for 2018 , g & a expenses of $ 60.1 million were essentially at the same level as in 2017. we experienced reductions in legal settlements , fines and contract labor , offset by increases for settlements related to the departure of certain executives , increases in medical claims and a buyout of an office lease . g & a on a per boe basis was $ 4.51 boe for 2018 compared to $ 4.10 boe for 2017. see financial statements and supplementary data – note 11 – share-based awards and cash-based awards under part ii , item 8 in this form 10-k for additional information . derivative gain . for 2018 , a $ 53.8 million derivative gain was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil during the second quarter of 2018 relating to a portion of our 2018 estimated production , which expired in december 2018. in the fourth quarter of 2018 , we entered into additional derivative contracts for crude oil and natural gas , which consists primarily of crude oil contracts with a term of 18 months . for 2017 , a $ 4.2 million derivative gain was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil and natural gas during the first quarter of 2017 relating to a portion of our 2017 estimated production and there were no open contracts as of december 31 , 2017. see financial

