we have historically increased our reserves and production through acquisitions , our drilling programs , and other projects that optimize production on existing wells . our production increased 11.3 % in 2019 from the prior year and we added 73.4 mmboe of proved reserves in 2019 , almost doubling our proved reserves and replacing our production by six times . the 87 % net increase in proved reserves year-over-year is primarily due to our acquisition of the mobile bay properties ( discussed below ) , as well as successful drilling , favorable technical revisions driven by improved well performance , recompletion , and workover efforts . partially offsetting these increases were decreases in proved reserves from lower commodity prices and production . during 2019 , we drilled and completed six additional wells which all began producing during 2019. in august 2019 , we acquired the mobile bay properties with the purchase of exxon 's interests in and operatorship of oil and gas producing properties in the eastern region of the gulf of mexico offshore alabama and related onshore and offshore facilities and pipelines . after taking into account customary closing adjustments and an effective date of january 1 , 2019 , cash consideration was $ 169.8 million , of which substantially all was paid by us at closing . we also assumed the related aro and certain other obligations associated with these assets . the acquisition was funded from cash on hand and borrowings of $ 150.0 million under the credit agreement , which were previously undrawn . as of december 31 , 2019 , the mobile bay properties had approximately 76.6 mmboe of net proved reserves , of which 99 % were proved developed producing reserves consisting primarily of natural gas and ngls with 20 % of the proved net reserves from liquids on a mmboe basis , based on sec pricing methodology . for the fourth quarter of 2019 , the average production of the mobile bay properties was approximately 18,500 net boe per day . the properties include working interests in nine gulf of mexico offshore producing fields and an onshore treatment facility that are adjacent to existing properties owned and operated by us . with this purchase , we became the largest operator in the area . 51 during 2019 , the percentage of our production from our fields on the conventional shelf increased to 73 % in 2019 from 59 % in 2018 of our total production ( measured on an mmboe basis ) primarily due to acquisition of the mobile bay properties and increases in production at the mahogany field . in the fourth quarter of 2019 , which included the mobile bay properties ' production for the entire quarter , the percentage of our production from our fields on the conventional shelf increased to 79 % measured on an mmboe basis . the mobile bay properties accounted for 35 % of our production measured on an mmboe basis in the fourth quarter of 2019. based on a reserve report prepared by nsai , our independent petroleum consultants , our total proved reserves at december 31 , 2019 were 157.4 mmboe compared to 84.0 mmboe as of december 31 , 2018. approximately 78 % of our proved reserves as of december 31 , 2019 were classified as proved developed producing , 7 % as proved developed non-producing and 15 % as proved undeveloped . classified by product , our proved reserves at december 31 , 2019 were 24 % crude oil , 16 % ngls and 60 % natural gas . these percentages and other energy-equivalent measurements stated in this form 10-k were determined using the industry standard energy-equivalent ratio of six mcf of natural gas to one bbl of crude oil , condensate or ngls . this energy-equivalent ratio does not assume price equivalency , and the energy-equivalent prices for crude oil , ngls and natural gas may differ significantly . our total proved reserves had an estimated pv-10 of $ 1,302.5 million before consideration of cash outflows related to aro . our pv-10 after considering future cash outflows related to aro was $ 1,117.6 million , and our standardized measure of discounted future cash flows was $ 986.9 million as of december 31 , 2019. neither pv-10 nor pv-10 after aro is a financial measure defined under gaap . for additional information about our proved reserves and a reconciliation of pv-10 and pv-10 after aro to the standardized measure of discounted future net cash flows , see properties – proved reserves under part i , item 2 in this form 10-k. to provide additional financial flexibility , we created the joint venture drilling program with private investors during 2018 and completed nine drilling projects by the end of 2019. the joint venture drilling program enables w & t to receive returns on its investment on a promoted basis and enables private investors to participate in certain drilling projects . it also allows more projects to be taken on with our capital expenditures budget , thereby helping us reduce our level of concentration risk via diversification . in the joint venture drilling program , five wells came on line during 2019 and four wells came on line during 2018. for the first half of 2020 , two wells are scheduled to be drilled and , assuming success , the wells are expected to start producing in late 2020 or early 2021. 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 joint venture drilling program . in october 2018 , we entered into a series of transactions to effect a refinancing of substantially all of our outstanding indebtedness . story_separator_special_tag lease operating expenses , which include base lease operating expenses , insurance premiums , workovers , and facilities maintenance expenses , increased $ 31.0 million , or 20.2 % , to $ 184.3 million in 2019 compared to $ 153.3 million in 2018. the acquisition of the mobile bay properties accounted for approximately half of the lease operating expense increase . on a per boe basis , lease operating expenses increased to $ 12.43 per boe during 2019 compared to $ 11.50 per boe during 2018. on a component basis , base lease operating expenses increased $ 17.6 million , insurance premiums increased $ 0.2 million , workover expenses increased $ 7.3 million and facilities maintenance expenses increased $ 5.9 million . base lease operating expenses increased primarily due to the addition of the mobile bay properties , acquired in august 2019 , and the heidelberg field , acquired in april 2018. the increase in workover expenses is primarily attributable to additional projects at our mahogany and gladden fields to increase production . the increase in facilities maintenance expenses involved several projects with no one project representing the majority of the increase . production taxes . production taxes were $ 2.5 million , an increase of $ 0.7 million due to the acquisition of the mobile bay properties . most of our production is from federal waters where no production taxes are imposed . the mobile bay properties and our fairway field , both of which are in state waters , are subject to production taxes . gathering and transportation costs . gathering and transportation costs increased to $ 26.0 million , or 15.9 % , in 2019 compared to $ 22.4 million in 2018 primarily related to the mobile bay properties and the heidelberg field . depreciation , depletion , amortization and accretion . dd & a , which includes accretion for aro , decreased to $ 10.01 per boe in 2019 from $ 11.24 per boe in 2018. on a nominal basis , dd & a decreased to $ 148.5 million ( 0.9 % ) in 2019 from $ 149.9 million in 2018. dd & a on a nominal basis decreased primarily due to a lower rate per boe due to the year-over-year increase in proved reserves . other factors affecting the dd & a rate are capital expenditures and changes in future development costs on remaining reserves . general and administrative expenses ( “ g & a ” ) . for 2019 , g & a expenses were $ 55.1 million compared to $ 60.1 million in 2018. we experienced reductions in expense primarily from higher overhead charged out ( credits ) on certain drilling projects ; lower medical claims ; lower incentive compensation expenses ; and lower surety bond expenses , partially offset by increased contractor and professional services expenses . g & a on a per boe basis was $ 3.72 boe for 2019 compared to $ 4.51 boe for 2018. derivative loss ( gain ) . for 2019 , a $ 59.9 million derivative loss was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil during the fourth quarter of 2019 for both certain crude oil and natural gas derivative contracts . for 2018 , a $ 53.8 million derivative gain was recorded for crude oil and natural gas derivative contracts . the gain in 2018 and loss in 2019 are primary due to crude oil prices falling in the latter months of 2018 and subsequently increasing in 2019 relative to the year-end 2018 crude oil prices , which impacted future prices used to value the derivative contracts in 2018 and 2019 , respectively . see financial statements and supplementary data – note 9 – derivative financial instruments under part ii , item 8 in this form 10-k for additional information . 55 interest expense , net . interest expense , net , was $ 59.6 million in 2019 , increasing 22.5 % from $ 48.6 million in 2018. the increase was primarily attributable to the issuance of the senior second lien notes , execution of the credit agreement and extinguishment of the company 's prior debt instruments ( the “ refinancing transaction ” ) . prior to the refinancing transaction , $ 25.6 million of interest costs on certain debt instruments for the period of january 1 , 2018 to october 18 , 2018 was recorded against the carrying value adjustments established under accounting standard codification topic 470-60 , troubled debt restructuring ( “ asc 470-60 ” ) . after the refinancing transaction , all of our interest cost is reported as interest expense . in addition , interest expense increased related to increased borrowings under the credit agreement in 2019 compared to 2018. partially offsetting the increase in interest expenses was an increase in interest income to $ 7.7 million in 2019 compared to $ 2.4 million in 2018 , primarily due to interest income related to the income tax refunds , apache and rik matters , each matter containing an element of interest income . see financial statements and supplementary data - note 2 – long-term debt under part ii , item 8 in this form 10-k for additional information on our debt . gain on exchange of debt . during 2018 , the refinancing transaction resulted in a gain of $ 47.1 million for 2018. 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 2019 , other expense , net , was $ 0.2 million , compared to $ 3.9 million of other income , net , for 2018. for 2019 , the amount consists primarily of federal royalty obligation reductions claimed in the current year related to capital deductions from prior periods , and partially offset by expenses related to the amortization of the

cash flows . net cash provided by operating activities for 2019 was $ 232.2 million , decreasing $ 89.5 million , or 27.8 % , from 2018. the change between periods is primarily due to lower realized prices for crude oil , ngls and natural gas , changes in cash advances and working capital changes , partially offset by increased volumes , lower spending for aro activities , derivatives and income tax refunds . our combined average realized sales price per boe decreased 17.5 % in 2019 , which caused total revenues to decrease $ 74.3 million , partially offset by increases of 11.3 % in overall production volumes which caused revenues to increase by $ 27.2 million . other items affecting operating cash flows for 2019 were : aro settlements of $ 11.4 million , which decreased from $ 28.6 million in 2018 ; cash advances from joint venture partners decreased $ 15.3 million during 2019 compared to an increase of $ 16.6 million during 2018 ; derivative receipts , net , were $ 13.9 million in 2019 compared to derivative cash payments , net , of $ 28.2 million in 2018 ; and income tax refunds were $ 51.8 million in 2019 compared to income tax refunds of $ 11.1 million in 2018. net cash used in investing activities during 2019 and 2018 was $ 313.8 million and $ 66.4 million , respectively , which represents our acquisitions and investments in oil and gas properties and equipment . investments in oil and natural gas properties 2019 were $ 125.7 million , which was an increase of $ 19.5 million from 2018. the majority of our capital expenditures for 2019 related to investments on the conventional shelf in the gulf of mexico and , to a lesser extent , in the deepwater of the gulf of mexico . the acquisition of property interest of $ 188.0 million was primarily related to the acquisition of the mobile bay properties and , to a lesser extent , the acquisition of the magnolia field .


 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.
     ```cash flows . net cash provided by operating activities for 2019 was $ 232.2 million , decreasing $ 89.5 million , or 27.8 % , from 2018. the change between periods is primarily due to lower realized prices for crude oil , ngls and natural gas , changes in cash advances and working capital changes , partially offset by increased volumes , lower spending for aro activities , derivatives and income tax refunds . our combined average realized sales price per boe decreased 17.5 % in 2019 , which caused total revenues to decrease $ 74.3 million , partially offset by increases of 11.3 % in overall production volumes which caused revenues to increase by $ 27.2 million . other items affecting operating cash flows for 2019 were : aro settlements of $ 11.4 million , which decreased from $ 28.6 million in 2018 ; cash advances from joint venture partners decreased $ 15.3 million during 2019 compared to an increase of $ 16.6 million during 2018 ; derivative receipts , net , were $ 13.9 million in 2019 compared to derivative cash payments , net , of $ 28.2 million in 2018 ; and income tax refunds were $ 51.8 million in 2019 compared to income tax refunds of $ 11.1 million in 2018. net cash used in investing activities during 2019 and 2018 was $ 313.8 million and $ 66.4 million , respectively , which represents our acquisitions and investments in oil and gas properties and equipment . investments in oil and natural gas properties 2019 were $ 125.7 million , which was an increase of $ 19.5 million from 2018. the majority of our capital expenditures for 2019 related to investments on the conventional shelf in the gulf of mexico and , to a lesser extent , in the deepwater of the gulf of mexico . the acquisition of property interest of $ 188.0 million was primarily related to the acquisition of the mobile bay properties and , to a lesser extent , the acquisition of the magnolia field .
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 Suspicious Activity Report : we have historically increased our reserves and production through acquisitions , our drilling programs , and other projects that optimize production on existing wells . our production increased 11.3 % in 2019 from the prior year and we added 73.4 mmboe of proved reserves in 2019 , almost doubling our proved reserves and replacing our production by six times . the 87 % net increase in proved reserves year-over-year is primarily due to our acquisition of the mobile bay properties ( discussed below ) , as well as successful drilling , favorable technical revisions driven by improved well performance , recompletion , and workover efforts . partially offsetting these increases were decreases in proved reserves from lower commodity prices and production . during 2019 , we drilled and completed six additional wells which all began producing during 2019. in august 2019 , we acquired the mobile bay properties with the purchase of exxon 's interests in and operatorship of oil and gas producing properties in the eastern region of the gulf of mexico offshore alabama and related onshore and offshore facilities and pipelines . after taking into account customary closing adjustments and an effective date of january 1 , 2019 , cash consideration was $ 169.8 million , of which substantially all was paid by us at closing . we also assumed the related aro and certain other obligations associated with these assets . the acquisition was funded from cash on hand and borrowings of $ 150.0 million under the credit agreement , which were previously undrawn . as of december 31 , 2019 , the mobile bay properties had approximately 76.6 mmboe of net proved reserves , of which 99 % were proved developed producing reserves consisting primarily of natural gas and ngls with 20 % of the proved net reserves from liquids on a mmboe basis , based on sec pricing methodology . for the fourth quarter of 2019 , the average production of the mobile bay properties was approximately 18,500 net boe per day . the properties include working interests in nine gulf of mexico offshore producing fields and an onshore treatment facility that are adjacent to existing properties owned and operated by us . with this purchase , we became the largest operator in the area . 51 during 2019 , the percentage of our production from our fields on the conventional shelf increased to 73 % in 2019 from 59 % in 2018 of our total production ( measured on an mmboe basis ) primarily due to acquisition of the mobile bay properties and increases in production at the mahogany field . in the fourth quarter of 2019 , which included the mobile bay properties ' production for the entire quarter , the percentage of our production from our fields on the conventional shelf increased to 79 % measured on an mmboe basis . the mobile bay properties accounted for 35 % of our production measured on an mmboe basis in the fourth quarter of 2019. based on a reserve report prepared by nsai , our independent petroleum consultants , our total proved reserves at december 31 , 2019 were 157.4 mmboe compared to 84.0 mmboe as of december 31 , 2018. approximately 78 % of our proved reserves as of december 31 , 2019 were classified as proved developed producing , 7 % as proved developed non-producing and 15 % as proved undeveloped . classified by product , our proved reserves at december 31 , 2019 were 24 % crude oil , 16 % ngls and 60 % natural gas . these percentages and other energy-equivalent measurements stated in this form 10-k were determined using the industry standard energy-equivalent ratio of six mcf of natural gas to one bbl of crude oil , condensate or ngls . this energy-equivalent ratio does not assume price equivalency , and the energy-equivalent prices for crude oil , ngls and natural gas may differ significantly . our total proved reserves had an estimated pv-10 of $ 1,302.5 million before consideration of cash outflows related to aro . our pv-10 after considering future cash outflows related to aro was $ 1,117.6 million , and our standardized measure of discounted future cash flows was $ 986.9 million as of december 31 , 2019. neither pv-10 nor pv-10 after aro is a financial measure defined under gaap . for additional information about our proved reserves and a reconciliation of pv-10 and pv-10 after aro to the standardized measure of discounted future net cash flows , see properties – proved reserves under part i , item 2 in this form 10-k. to provide additional financial flexibility , we created the joint venture drilling program with private investors during 2018 and completed nine drilling projects by the end of 2019. the joint venture drilling program enables w & t to receive returns on its investment on a promoted basis and enables private investors to participate in certain drilling projects . it also allows more projects to be taken on with our capital expenditures budget , thereby helping us reduce our level of concentration risk via diversification . in the joint venture drilling program , five wells came on line during 2019 and four wells came on line during 2018. for the first half of 2020 , two wells are scheduled to be drilled and , assuming success , the wells are expected to start producing in late 2020 or early 2021. 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 joint venture drilling program . in october 2018 , we entered into a series of transactions to effect a refinancing of substantially all of our outstanding indebtedness . story_separator_special_tag lease operating expenses , which include base lease operating expenses , insurance premiums , workovers , and facilities maintenance expenses , increased $ 31.0 million , or 20.2 % , to $ 184.3 million in 2019 compared to $ 153.3 million in 2018. the acquisition of the mobile bay properties accounted for approximately half of the lease operating expense increase . on a per boe basis , lease operating expenses increased to $ 12.43 per boe during 2019 compared to $ 11.50 per boe during 2018. on a component basis , base lease operating expenses increased $ 17.6 million , insurance premiums increased $ 0.2 million , workover expenses increased $ 7.3 million and facilities maintenance expenses increased $ 5.9 million . base lease operating expenses increased primarily due to the addition of the mobile bay properties , acquired in august 2019 , and the heidelberg field , acquired in april 2018. the increase in workover expenses is primarily attributable to additional projects at our mahogany and gladden fields to increase production . the increase in facilities maintenance expenses involved several projects with no one project representing the majority of the increase . production taxes . production taxes were $ 2.5 million , an increase of $ 0.7 million due to the acquisition of the mobile bay properties . most of our production is from federal waters where no production taxes are imposed . the mobile bay properties and our fairway field , both of which are in state waters , are subject to production taxes . gathering and transportation costs . gathering and transportation costs increased to $ 26.0 million , or 15.9 % , in 2019 compared to $ 22.4 million in 2018 primarily related to the mobile bay properties and the heidelberg field . depreciation , depletion , amortization and accretion . dd & a , which includes accretion for aro , decreased to $ 10.01 per boe in 2019 from $ 11.24 per boe in 2018. on a nominal basis , dd & a decreased to $ 148.5 million ( 0.9 % ) in 2019 from $ 149.9 million in 2018. dd & a on a nominal basis decreased primarily due to a lower rate per boe due to the year-over-year increase in proved reserves . other factors affecting the dd & a rate are capital expenditures and changes in future development costs on remaining reserves . general and administrative expenses ( “ g & a ” ) . for 2019 , g & a expenses were $ 55.1 million compared to $ 60.1 million in 2018. we experienced reductions in expense primarily from higher overhead charged out ( credits ) on certain drilling projects ; lower medical claims ; lower incentive compensation expenses ; and lower surety bond expenses , partially offset by increased contractor and professional services expenses . g & a on a per boe basis was $ 3.72 boe for 2019 compared to $ 4.51 boe for 2018. derivative loss ( gain ) . for 2019 , a $ 59.9 million derivative loss was recorded for crude oil and natural gas derivative contracts . we entered into derivative contracts for crude oil during the fourth quarter of 2019 for both certain crude oil and natural gas derivative contracts . for 2018 , a $ 53.8 million derivative gain was recorded for crude oil and natural gas derivative contracts . the gain in 2018 and loss in 2019 are primary due to crude oil prices falling in the latter months of 2018 and subsequently increasing in 2019 relative to the year-end 2018 crude oil prices , which impacted future prices used to value the derivative contracts in 2018 and 2019 , respectively . see financial statements and supplementary data – note 9 – derivative financial instruments under part ii , item 8 in this form 10-k for additional information . 55 interest expense , net . interest expense , net , was $ 59.6 million in 2019 , increasing 22.5 % from $ 48.6 million in 2018. the increase was primarily attributable to the issuance of the senior second lien notes , execution of the credit agreement and extinguishment of the company 's prior debt instruments ( the “ refinancing transaction ” ) . prior to the refinancing transaction , $ 25.6 million of interest costs on certain debt instruments for the period of january 1 , 2018 to october 18 , 2018 was recorded against the carrying value adjustments established under accounting standard codification topic 470-60 , troubled debt restructuring ( “ asc 470-60 ” ) . after the refinancing transaction , all of our interest cost is reported as interest expense . in addition , interest expense increased related to increased borrowings under the credit agreement in 2019 compared to 2018. partially offsetting the increase in interest expenses was an increase in interest income to $ 7.7 million in 2019 compared to $ 2.4 million in 2018 , primarily due to interest income related to the income tax refunds , apache and rik matters , each matter containing an element of interest income . see financial statements and supplementary data - note 2 – long-term debt under part ii , item 8 in this form 10-k for additional information on our debt . gain on exchange of debt . during 2018 , the refinancing transaction resulted in a gain of $ 47.1 million for 2018. 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 2019 , other expense , net , was $ 0.2 million , compared to $ 3.9 million of other income , net , for 2018. for 2019 , the amount consists primarily of federal royalty obligation reductions claimed in the current year related to capital deductions from prior periods , and partially offset by expenses related to the amortization of the

