during 2018 , average nymex oil and gas prices were $ 64.77 per barrel and $ 3.09 per mcf , respectively , representing an increase of 27 % and a decrease of 1 % , respectively , from the average nymex oil and gas prices for 2017 . local market prices for oil and gas can be impacted by pipeline capacity constraints limiting takeaway and increasing basis differentials . gas production growth and pipeline constraints in the permian basin and mid-continent region and oil production growth and pipeline constraints in the permian basin have resulted in higher basis differentials and , therefore , lower realized prices . the average prices per barrel of oil and mcf of gas that we realized were less than the wti cushing and henry hub indices by the amounts shown in the table below for the periods indicated . replace_table_token_16_th pipeline expansion projects in the permian basin are expected to ease capacity constraints as they come online over the next few years , which is reflected in the current futures markets that show narrowing differentials . however , if pipeline constraints remain , higher differentials will persist or potentially worsen . our revenue , profitability , and future growth are highly dependent on the prices we receive for our oil and gas production . see results of operations revenues below for further information regarding our realized commodity prices . 38 2018 summary of operating and financial results total daily production volumes increased 17 % to 221.9 mboe per day . oil volumes increased 18 % to 67.7 mbbls per day . gas volumes increased 10 % to 563.9 mmcf per day . ngl volumes increased 27 % to 60.3 mbbls per day . total production revenue increased 23 % to $ 2.30 billion . year-end proved reserves increased 6 % to 591.2 mmboe , as compared to 559.0 mmboe at year-end 2017 . exploration and development capital investments were $ 1.57 billion , as compared to $ 1.28 billion in 2017 . cash flow provided by operating activities increased 41 % to $ 1.55 billion . cash on hand at december 31 , 2018 was $ 800.7 million . for the year ended december 31 , 2018 , we had net income of $ 791.9 million ( $ 8.32 per diluted share ) as compared to net income of $ 494.3 million ( $ 5.19 per diluted share ) in 2017 . production revenue in 2018 was positively impacted by increased production volumes across all products as well as increased realized oil and ngl commodity prices . lower realized gas prices negatively impacted 2018. year-over-year changes are discussed further in the results of operations section that follows . proved reserves our proved reserves by region at december 31 , 2018 and 2017 were as follows : replace_table_token_17_th replace_table_token_18_th year-end 2018 proved reserves increased approximately 6 % to 591.2 mmboe , compared to 559.0 mmboe at year-end 2017 . proved gas reserves were 1.59 tcf , proved oil reserves were 146.5 mmbbls , and proved ngl reserves were 179.4 mmbbls . reserves in the permian basin accounted for 57 % of our total proved reserves with nearly all of the remainder in our mid-continent region . see supplemental information on oil and gas producing activities ( unaudited ) in item 8 for a more detailed discussion regarding year-over-year changes in our proved reserves . 39 the process of estimating quantities of oil , gas , and ngl reserves is complex . significant decisions are required in the evaluation of all available geological , geophysical , engineering , and economic data . although every reasonable effort is made to ensure that our reserve estimates represent the most accurate assessments possible , subjective decisions and available data for our various fields make these estimates generally less precise than other estimates included in financial statement disclosures . see proved reserves estimation procedures in items 1 and 2 for a discussion of our reserve estimation process and item 1a risk factors , which includes a discussion of factors that affect our proved reserves estimates . results of operations effective january 1 , 2018 , we adopted the provisions of accounting standards codification 606 , revenue from contracts with customers ( “ asc 606 ” ) , utilizing the modified retrospective approach , which we applied to contracts that were not completed as of that date . because we utilized the modified retrospective approach , there was no impact to prior periods ' reported amounts . application of asc 606 has no impact on our net income or cash flows from operations ; however , certain costs classified as transportation , processing , and other operating in the statement of operations under prior accounting standards are now reflected as deductions from revenue under asc 606. the following table presents the impact on our oil sales , gas sales , and ngl sales and on our transportation , processing , and other operating costs from the application of asc 606 in the current reporting period : replace_table_token_19_th almost all our revenues are derived from sales of our oil , natural gas , and ngl production . increases or decreases in our revenues , profitability , and future production growth are highly dependent on the commodity prices we receive . prices are market driven and we expect that future prices will continue to fluctuate due to supply and demand factors , availability of transportation , seasonality , geopolitical , and economic factors . see item 7a quantitative and qualitative disclosures about market risk for more information regarding the sensitivity of our revenues to price fluctuations . story_separator_special_tag we remeasured the deferred tax assets and liabilities as of december 31 , 2017 to reflect the reduction in the u.s. income tax rate from 35 % to 21 % for years after 2017 and , as a result of this remeasurement , we recorded an income tax benefit of $ 61.1 million and a corresponding $ 61.1 million decrease in the net deferred tax liabilities as of december 31 , 2017. we believe the accounting for the effects of h.r.1 recognized in the december 31 , 2017 financial statements is materially complete . during 2018 , no other adjustments were made . as a result of h.r.1 , we expect our effective 46 tax rate in future periods will be lower than in periods prior to enactment . in addition , the limitations on utilization of net operating losses and deductibility of interest and executive compensation may result in the payment of cash taxes earlier than expected . our combined federal and state effective tax rates , as shown above , differ from the statutory rate primarily due to state income taxes , non-deductible expenses , revisions , and the impact of changes in tax law . see note 9 to the consolidated financial statements for further information regarding our income taxes . results of operations 2017 compared to 2016 summary for the year ended december 31 , 2017 , we had net income of $ 494.3 million ( $ 5.19 per diluted share ) , up from a net loss of $ 408.8 million ( $ 4.38 per diluted share ) in 2016 . production revenue in 2017 was positively impacted by increased realized commodity prices and production volumes . lower commodity prices negatively impacted 2016 , including resulting in $ 757.7 million of impairments of our oil and gas properties in that year . year-over-year changes are discussed further as follows . also refer to the “ 2018 compared to 2017 ” section above for general information regarding various statement of operations line items . revenues realized prices and production volumes were higher in 2017 as compared to 2016 , which caused our revenues to increase by $ 652.8 million , or 53 % , from the prior year . the following table shows our production revenue for the years indicated as well as the change in revenue due to changes in prices and volumes . replace_table_token_31_th the table below presents our production volumes by commodity , our average realized commodity prices , and certain major u.s. index prices . the sale of our permian basin oil production is typically tied to the wti midland benchmark price and the sale of our mid-continent oil production is typically tied to the wti cushing benchmark price . during 2017 and 2016 , 78 % and 80 % , respectively , of our oil production was in the permian basin with the majority of the remainder in the mid-continent region . our realized prices do not include settlements of commodity derivative contracts . 47 replace_table_token_32_th other revenues we transport , process , and market some third-party gas that is associated with our equity gas . we market and sell gas for other working interest owners under short term agreements and may earn a fee for such services . the table below reflects income from third-party gas gathering and processing and our net marketing margin for marketing third-party gas . replace_table_token_33_th fluctuations in revenues from gas gathering and gas marketing activities are a function of increases and decreases in volumes , commodity prices , and gathering rate charges . the increases from 2016 are primarily due to an increase in prices . 48 operating costs and expenses total operating costs and expenses of $ 1.17 billion in 2017 were 36 % lower than the $ 1.83 billion incurred in 2016 . most of the decrease resulted from ceiling test impairments of our oil and gas properties of $ 757.7 million recorded in 2016 ; we recorded no ceiling test impairments in 2017. also contributing to the decrease was the net gain on derivative instruments in 2017 compared to a net loss in 2016. otherwise , all other categories of operating costs and expenses increased in 2017. the following table shows our operating costs and expenses for the years indicated and a discussion of year-over-year differences follows . replace_table_token_34_th ceiling test impairment we use the full cost method of accounting for our oil and gas operations . accounting rules require us to perform a quarterly ceiling test calculation to test our capitalized oil and gas property costs for possible impairment . if the net capitalized cost of our oil and gas properties , as adjusted for income taxes , exceeds the ceiling limitation , the excess is charged to expense . the ceiling limitation is equal to the sum of : ( i ) the present value discounted at 10 % of estimated future net revenues from proved reserves , ( ii ) the cost of properties not being amortized , and ( iii ) the lower of cost or estimated fair value of unproven properties included in the costs being amortized , as adjusted for income taxes . estimated future net revenues are determined based on trailing twelve-month average commodity prices and estimated proved reserve quantities , operating costs , and capital expenditures . at each quarter-end date during the year ended december 31 , 2017 , the net capitalized cost of our oil and gas properties , as adjusted for income taxes , did not exceed the ceiling limitation , and , therefore , we did not recognize a ceiling test impairment during the year . the commodity prices used in the december 31 , 2017 ceiling calculation , based on the required trailing twelve-month average prices , were $ 2.98 per mcf of gas and $ 51.34 per barrel of oil . a decline of approximately 19 % or more in the value of the ceiling limitation would have

net cash provided by operating activities in 2018 was $ 1.55 billion , up $ 454.4 million , or 41 % , from $ 1.10 billion in 2017 . the increase was primarily a result of higher revenues due to higher production volumes and realized oil and ngl prices in 2018 . also contributing to the increase was a decreased investment in working capital , primarily caused by the timing of cash receipts of accounts receivable . these increases were partially offset by increased net operating expenses , primarily production expense and taxes other than income , and increased cash outflows for settlements of derivative instruments . net cash provided by operating activities in 2017 was $ 1.10 billion , up $ 470.7 million , or 75 % , from $ 625.8 million in 2016. the increase was primarily a result of higher revenue due to higher realized prices and production volumes in 2017. this increase was partially offset by increased operating expenses and an increased investment in working capital . see results of operations above for more information regarding year-over-year changes in revenue and operating expenses . in 2018 , net cash used by investing activities was $ 1.09 billion , compared to $ 1.27 billion and $ 692.4 million in 2017 and 2016 , respectively . the majority of our cash flows used by investing activities are for e & d capital expenditures , which , as reflected in the statements of cash flows , were $ 1.57 billion , $ 1.23 billion , and $ 699.6 million in 2018 , 2017 , and 2016 , respectively . our other capital expenditures , which are primarily for our midstream assets , were $ 103.5 million , $ 45.4 million , and $ 22.2 million in 2018 , 2017 , and 2016 , respectively .


 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.
     ```net cash provided by operating activities in 2018 was $ 1.55 billion , up $ 454.4 million , or 41 % , from $ 1.10 billion in 2017 . the increase was primarily a result of higher revenues due to higher production volumes and realized oil and ngl prices in 2018 . also contributing to the increase was a decreased investment in working capital , primarily caused by the timing of cash receipts of accounts receivable . these increases were partially offset by increased net operating expenses , primarily production expense and taxes other than income , and increased cash outflows for settlements of derivative instruments . net cash provided by operating activities in 2017 was $ 1.10 billion , up $ 470.7 million , or 75 % , from $ 625.8 million in 2016. the increase was primarily a result of higher revenue due to higher realized prices and production volumes in 2017. this increase was partially offset by increased operating expenses and an increased investment in working capital . see results of operations above for more information regarding year-over-year changes in revenue and operating expenses . in 2018 , net cash used by investing activities was $ 1.09 billion , compared to $ 1.27 billion and $ 692.4 million in 2017 and 2016 , respectively . the majority of our cash flows used by investing activities are for e & d capital expenditures , which , as reflected in the statements of cash flows , were $ 1.57 billion , $ 1.23 billion , and $ 699.6 million in 2018 , 2017 , and 2016 , respectively . our other capital expenditures , which are primarily for our midstream assets , were $ 103.5 million , $ 45.4 million , and $ 22.2 million in 2018 , 2017 , and 2016 , respectively .
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 Suspicious Activity Report : during 2018 , average nymex oil and gas prices were $ 64.77 per barrel and $ 3.09 per mcf , respectively , representing an increase of 27 % and a decrease of 1 % , respectively , from the average nymex oil and gas prices for 2017 . local market prices for oil and gas can be impacted by pipeline capacity constraints limiting takeaway and increasing basis differentials . gas production growth and pipeline constraints in the permian basin and mid-continent region and oil production growth and pipeline constraints in the permian basin have resulted in higher basis differentials and , therefore , lower realized prices . the average prices per barrel of oil and mcf of gas that we realized were less than the wti cushing and henry hub indices by the amounts shown in the table below for the periods indicated . replace_table_token_16_th pipeline expansion projects in the permian basin are expected to ease capacity constraints as they come online over the next few years , which is reflected in the current futures markets that show narrowing differentials . however , if pipeline constraints remain , higher differentials will persist or potentially worsen . our revenue , profitability , and future growth are highly dependent on the prices we receive for our oil and gas production . see results of operations revenues below for further information regarding our realized commodity prices . 38 2018 summary of operating and financial results total daily production volumes increased 17 % to 221.9 mboe per day . oil volumes increased 18 % to 67.7 mbbls per day . gas volumes increased 10 % to 563.9 mmcf per day . ngl volumes increased 27 % to 60.3 mbbls per day . total production revenue increased 23 % to $ 2.30 billion . year-end proved reserves increased 6 % to 591.2 mmboe , as compared to 559.0 mmboe at year-end 2017 . exploration and development capital investments were $ 1.57 billion , as compared to $ 1.28 billion in 2017 . cash flow provided by operating activities increased 41 % to $ 1.55 billion . cash on hand at december 31 , 2018 was $ 800.7 million . for the year ended december 31 , 2018 , we had net income of $ 791.9 million ( $ 8.32 per diluted share ) as compared to net income of $ 494.3 million ( $ 5.19 per diluted share ) in 2017 . production revenue in 2018 was positively impacted by increased production volumes across all products as well as increased realized oil and ngl commodity prices . lower realized gas prices negatively impacted 2018. year-over-year changes are discussed further in the results of operations section that follows . proved reserves our proved reserves by region at december 31 , 2018 and 2017 were as follows : replace_table_token_17_th replace_table_token_18_th year-end 2018 proved reserves increased approximately 6 % to 591.2 mmboe , compared to 559.0 mmboe at year-end 2017 . proved gas reserves were 1.59 tcf , proved oil reserves were 146.5 mmbbls , and proved ngl reserves were 179.4 mmbbls . reserves in the permian basin accounted for 57 % of our total proved reserves with nearly all of the remainder in our mid-continent region . see supplemental information on oil and gas producing activities ( unaudited ) in item 8 for a more detailed discussion regarding year-over-year changes in our proved reserves . 39 the process of estimating quantities of oil , gas , and ngl reserves is complex . significant decisions are required in the evaluation of all available geological , geophysical , engineering , and economic data . although every reasonable effort is made to ensure that our reserve estimates represent the most accurate assessments possible , subjective decisions and available data for our various fields make these estimates generally less precise than other estimates included in financial statement disclosures . see proved reserves estimation procedures in items 1 and 2 for a discussion of our reserve estimation process and item 1a risk factors , which includes a discussion of factors that affect our proved reserves estimates . results of operations effective january 1 , 2018 , we adopted the provisions of accounting standards codification 606 , revenue from contracts with customers ( “ asc 606 ” ) , utilizing the modified retrospective approach , which we applied to contracts that were not completed as of that date . because we utilized the modified retrospective approach , there was no impact to prior periods ' reported amounts . application of asc 606 has no impact on our net income or cash flows from operations ; however , certain costs classified as transportation , processing , and other operating in the statement of operations under prior accounting standards are now reflected as deductions from revenue under asc 606. the following table presents the impact on our oil sales , gas sales , and ngl sales and on our transportation , processing , and other operating costs from the application of asc 606 in the current reporting period : replace_table_token_19_th almost all our revenues are derived from sales of our oil , natural gas , and ngl production . increases or decreases in our revenues , profitability , and future production growth are highly dependent on the commodity prices we receive . prices are market driven and we expect that future prices will continue to fluctuate due to supply and demand factors , availability of transportation , seasonality , geopolitical , and economic factors . see item 7a quantitative and qualitative disclosures about market risk for more information regarding the sensitivity of our revenues to price fluctuations . story_separator_special_tag we remeasured the deferred tax assets and liabilities as of december 31 , 2017 to reflect the reduction in the u.s. income tax rate from 35 % to 21 % for years after 2017 and , as a result of this remeasurement , we recorded an income tax benefit of $ 61.1 million and a corresponding $ 61.1 million decrease in the net deferred tax liabilities as of december 31 , 2017. we believe the accounting for the effects of h.r.1 recognized in the december 31 , 2017 financial statements is materially complete . during 2018 , no other adjustments were made . as a result of h.r.1 , we expect our effective 46 tax rate in future periods will be lower than in periods prior to enactment . in addition , the limitations on utilization of net operating losses and deductibility of interest and executive compensation may result in the payment of cash taxes earlier than expected . our combined federal and state effective tax rates , as shown above , differ from the statutory rate primarily due to state income taxes , non-deductible expenses , revisions , and the impact of changes in tax law . see note 9 to the consolidated financial statements for further information regarding our income taxes . results of operations 2017 compared to 2016 summary for the year ended december 31 , 2017 , we had net income of $ 494.3 million ( $ 5.19 per diluted share ) , up from a net loss of $ 408.8 million ( $ 4.38 per diluted share ) in 2016 . production revenue in 2017 was positively impacted by increased realized commodity prices and production volumes . lower commodity prices negatively impacted 2016 , including resulting in $ 757.7 million of impairments of our oil and gas properties in that year . year-over-year changes are discussed further as follows . also refer to the “ 2018 compared to 2017 ” section above for general information regarding various statement of operations line items . revenues realized prices and production volumes were higher in 2017 as compared to 2016 , which caused our revenues to increase by $ 652.8 million , or 53 % , from the prior year . the following table shows our production revenue for the years indicated as well as the change in revenue due to changes in prices and volumes . replace_table_token_31_th the table below presents our production volumes by commodity , our average realized commodity prices , and certain major u.s. index prices . the sale of our permian basin oil production is typically tied to the wti midland benchmark price and the sale of our mid-continent oil production is typically tied to the wti cushing benchmark price . during 2017 and 2016 , 78 % and 80 % , respectively , of our oil production was in the permian basin with the majority of the remainder in the mid-continent region . our realized prices do not include settlements of commodity derivative contracts . 47 replace_table_token_32_th other revenues we transport , process , and market some third-party gas that is associated with our equity gas . we market and sell gas for other working interest owners under short term agreements and may earn a fee for such services . the table below reflects income from third-party gas gathering and processing and our net marketing margin for marketing third-party gas . replace_table_token_33_th fluctuations in revenues from gas gathering and gas marketing activities are a function of increases and decreases in volumes , commodity prices , and gathering rate charges . the increases from 2016 are primarily due to an increase in prices . 48 operating costs and expenses total operating costs and expenses of $ 1.17 billion in 2017 were 36 % lower than the $ 1.83 billion incurred in 2016 . most of the decrease resulted from ceiling test impairments of our oil and gas properties of $ 757.7 million recorded in 2016 ; we recorded no ceiling test impairments in 2017. also contributing to the decrease was the net gain on derivative instruments in 2017 compared to a net loss in 2016. otherwise , all other categories of operating costs and expenses increased in 2017. the following table shows our operating costs and expenses for the years indicated and a discussion of year-over-year differences follows . replace_table_token_34_th ceiling test impairment we use the full cost method of accounting for our oil and gas operations . accounting rules require us to perform a quarterly ceiling test calculation to test our capitalized oil and gas property costs for possible impairment . if the net capitalized cost of our oil and gas properties , as adjusted for income taxes , exceeds the ceiling limitation , the excess is charged to expense . the ceiling limitation is equal to the sum of : ( i ) the present value discounted at 10 % of estimated future net revenues from proved reserves , ( ii ) the cost of properties not being amortized , and ( iii ) the lower of cost or estimated fair value of unproven properties included in the costs being amortized , as adjusted for income taxes . estimated future net revenues are determined based on trailing twelve-month average commodity prices and estimated proved reserve quantities , operating costs , and capital expenditures . at each quarter-end date during the year ended december 31 , 2017 , the net capitalized cost of our oil and gas properties , as adjusted for income taxes , did not exceed the ceiling limitation , and , therefore , we did not recognize a ceiling test impairment during the year . the commodity prices used in the december 31 , 2017 ceiling calculation , based on the required trailing twelve-month average prices , were $ 2.98 per mcf of gas and $ 51.34 per barrel of oil . a decline of approximately 19 % or more in the value of the ceiling limitation would have

