Editor’s note: Be sure to check out our look at the top exploration and development stories on Dec. 27, and the top deals in oil and gas of 2018 coming Dec. 28. Following the New Year, we’ll look at the top trends to watch in 2019 on Jan. 2.

What can we make of oil and gas in 2018? The year started out with much promise for producers and, despite hiccups along the way, it was still a good year to be in the business.

Oil prices started high, but fell. However, rig counts rose and billion-dollar deals took place. The Permian Basin continued to proliferate. The Bakken returned to the spotlight.

U.S. shale producers upped their game in 2018, setting a record for oil production. They also exported more oil and gas than ever before, making the country a net oil exporter for the first time.

Geopolitical factors weighed heavily on the industry, from Iran sanctions to tariff wars. Tariffs even took their toll on the up-and-coming solar industry.

We uttered the word “bottleneck” more than any of us wanted to as producers thirsted for relief and oil and gas scribes thirsted for a new story.

Below is a look back at the top storylines that shaped the oil and gas industry in 2018. There are more, certainly, such as the Mid-Cush differential, completion technology advances and even electric vehicle demand. But these are the stories that dominated the news throughout the year.

Oil Price Roller Coaster

Oil in the $70s? It happened. In fact, Brent hit the $80 per barrel (bbl) mark in May for the first time in three years. As December came to a close, prices fell into the $40s. (At the time of this posting WTI was $47.92)

Oil prices were affected by numerous factors throughout the year, as noted weekly by Stratas Advisors’ “What’s Affecting Oil Prices This Week?” However, nothing turned the wheels of the industry more than the roller coaster ride of oil prices in 2018.

The year became an ongoing saga of will they or won’t they?, as analysts tried to predict whether OPEC would make the necessary production cuts to keep markets in balance. In the end, it did, at least for the time being.

At the Dec. 7 OPEC and Non-OPEC meeting, the cartel and its partners overcame last-minute drama from Russia and Iran to settle on a six-month, 1.2 million barrel per day (MMbbl/d) oil production cut. This, despite repeated calls and tweets throughout the year from U.S. President Donald Trump to not cut production and to let oil prices fall. He openly, and somewhat mistakenly, blamed OPEC for the sole fate of oil prices in the U.S.

It also came despite a power play by Russia, which saw its energy minister leave the Vienna meetings to consult with Russia President Vladimir Putin. The move left some industry watchers to start questioning who is actually running OPEC these days.

Bottlenecks, Bottlenecks And, Hey, Bottlenecks

If you had to choose one word of the year in the oil and gas industry it would almost certainly have to be “bottlenecks,” with “Mid-Cush” a close second. From the Permian to Appalachia to the ship channels of Texas and the Atlantic Coast, U.S. production bottleneck talk was everywhere. As U.S. production ramped up to record levels in 2018, the need for infrastructure to accommodate it became one of the hot topics in the industry.

Ground zero for the pipeline crunch is Texas as the Permian rig count rose steadily and the barrels flowed. It was estimated that producers were losing more than $1 billion per day due to lack of infrastructure. Some wondered if the pipeline shortage put Permian crude and NGL production at risk.

Meanwhile, the differential between Midland prices and Cushing prices left Permian refiners paying a hefty price for crude.

RELATED VIDEO: Sean Strawbridge, CEO of the Port of Corpus Christi, talks Permian bottlenecks

Appalachia saw its fair share of pipeline problems as well. Some of that was due to regulatory woes in New York that led to a Russian LNG tanker arriving in Boston Harbor. Otherwise, getting natural gas out of the Marcellus has proved problematic. But there was notable relief in 2018 when Williams finished the Atlantic Sunrise connection that helped open up the flow of natural gas to the Atlantic seaboard and points south.

RELATED VIDEO: Hart Energy tours the Atlantic Sunrise project in Lancaster, Pa.

Colorado Ballot Initiative

The November midterm elections were full of intrigue on many fronts. While much of the country was fixated on the balance of Congress, the oil and gas industry was also keeping a close watch on the Colorado ballot initiative, Proposition 112, which would have mandated at least 2,500 ft (762 m) of separation between new drilling activities and occupied or vulnerable areas. Had it passed, questions about the viability of the state’s oil and gas industry would have swiftly emerged. As it was, the initiative cost oil and gas companies billions of dollars while the process played out.

In the end, the measure ended up garnering only 43% of the vote. Shares of producers active in the state, including Anadarko Petroleum Corp. (NYSE: APC), Noble Energy Inc. (NYSE: NBL) and Devon Energy Corp. (NYSE: DVN), rose on Nov. 7, retracing some of their double-digit percentage declines since the initiative went on the state's ballot.

Other ballot initiatives in Washington state and Arizona also fell flat.

But analysts warned that such measures were sure to come about again, as Reed Olmstead, IHS Markit, told Hart Energy during the Executive Oil Conference in Midland on election day.

Energy Cabinet Overhaul

The year started with at least four faces familiar to the oil and gas industry occupying high-level cabinet positions within the Trump administration. When the year ended, only former Texas Gov. Rick Perry remained as Energy Secretary. Along the way, former Exxon Mobil CEO Rex Tillerson (Secretary of State), Scott Pruitt (EPA administrator) and Ryan Zinke (Interior Secretary) were all forced out as the massive changeover of Trump’s cabinet continued.

Tillerson was first, resigning in March. Trump publicly undercut Tillerson’s diplomatic initiatives numerous times, including when his comments about Russia appeared to be at odds with those of the White House.

In December, Tillerson had some strong criticism of the president in a rare public appearance in Houston. (See video via FOX News: https://bit.ly/2LqH9LX)

On July 5, Pruitt handed in his resignation, and Deputy Administrator Andrew Wheeler took his place. Pruitt was one of Trump’s most polarizing Cabinet members, slashing regulations on the energy and manufacturing industries, including a move to repeal former President Barack Obama’s signature program to cut carbon emissions from power plants, dubbed the Clean Power Plan.

He was also instrumental in lobbying Trump to withdraw the U.S. from the 2015 Paris climate accord to combat global warming.

But a string of controversies eventually caught up to Pruitt.

Wheeler, a former mining industry lobbyist, has kept up the policies started under Pruitt. At the time, Matt Dempsey, an energy lobbyist at consultancy FTI, said Wheeler will be less controversial than Pruitt but without altering the agenda. That prediction has proved true, so far.

In December, Zinke, also mired in controversial missteps, resigned from the Department of the Interior. He was among Trump's most active Cabinet members, cutting huge wilderness national monuments in Utah to a fraction of their size and proposing offshore oil drilling in the Arctic, Pacific and Atlantic. Those activities made him a prime target for conservationists and environmental groups.

Trade Uncertainty

From Mexico’s new president to the renegotiation of NAFTA and Iran sanctions to a tariff battle with China, the uncertainty over trade and exports hung over the energy industry all year. But that doesn’t mean it was all bad.

In fact, U.S. exports of LNG really got going in 2018. Cheniere Energy CEO Jack Fusco discussed the U.S. as an LNG exporter during a speech to the Texas Oil & Gas Association in October.

But uncertainty in Mexico’s new position over foreign investment in its energy sector picked up when the country elected leftist President Andres Manuel Lopez Obrador. Shortly after the election in July, Mexico scrapped plans for a new oil auction.

Lopez Obrador took office on Dec. 1, promising to increase the government’s role in the energy industry and roll back what he described as a 36-year neo-liberal era in which successive governments gradually opened up the economy. During the election campaign, he pledged to review the oil and gas contracts for any signs of corruption. He and his team have not said they have uncovered any wrongdoing in the contracts already awarded.

“The contracts will not be canceled, so there won’t be a loss of confidence,” he told reporters at a daily news conference.

While the USMCA, also known as the “new NAFTA,” largely focused on the automotive industry, some provisions were wins for the oil and gas industry that promise to spur further investment, exploration and production. The new framework requires that the U.S. government automatically approve any gas exports to Mexico. Meanwhile, a dispute resolution process that allows multinational corporations to sue governments over regulatory changes has been preserved for the oil and gas industry, prompting objections from environmentalists.

U.S. Becomes Net Oil Exporter

As far as oil is concerned, the U.S reached a milestone late in 2018 when it became a net oil exporter for the first time, according the EIA. The milestone came just three years after the U.S. ended a four-decade moratorium on exports of its crude oil.

“While the large crude oil inventory drop was notable, the surge in exports of crude oil to over 3 million barrels per day was remarkable,” John Kilduff, partner at energy hedge fund Again Capital LLC in New York, told Reuters when EIA made its announcement on Dec. 6.

Wolfcamp’s, Bone Spring’s Potentially Prolific Bounty

Also on Dec. 6, the U.S. Geological Survey issues a report expanding the Permian’s Wolfcamp, Bone Spring potential bounty to an estimated 46.3 Bbbl of oil plus 281 Tcfof gas and 20 Bbbl of NGL. That’s more than double the previous estimate.

While the prolific Permian was already a hot commodity, news of such potential is sure to make the attention it receives in 2019 scorching. The EIA forecasted oil production in the Permian will rise by 63,000 bbl/d to about 3.7 MMbbl/d in December.

“At the resource level, the Permian remains king,” Stephen Beck, senior director of upstream for Stratas Advisors, said in a recently released 2019 outlook. “Current 2019 estimates for the Wolfcamp, Bone Spring and related reservoirs have production averaging 5.9 MMboe per day (million barrels of oil equivalent per day). Breaking this down, the Delaware sub-basin Wolfcamp contributes 50%, the Midland sub-basin Wolfcamp 32% and the Bone Spring 18%.”

Climate Change Pressures From Activist Investors

Environmentalists, politicians and even celebrities have certainly had a lot to say about climate change and the oil and gas industry. But it’s the pressure being driven by investors that has had the most effect on the sector. Before the year closed, Chevron and Equinor became the latest targets of activist investors moving to force five of the biggest oil companies to commit to fixed emissions targets and align with the Paris climate agreement.

The activist investors of Chevron Corp. said on Dec. 19 they had filed annual meeting resolutions calling for the oil company to embrace greenhouse gas reductions.

In Europe, Follow This filed a climate resolution for Equinor’s 2019 annual general meeting, mirroring its activist moves on BP (NYSE: BP) and Royal Dutch Shell (NYSE: RDS.A). A spokesman for Equinor said it was supporting the Paris climate agreement.

“We have our own climate roadmap and clear goals for how to cut CO2 emission,” he said.

Earlier in the year, Shell made a U-turn. setting out plans to introduce three-year or five-year carbon emissions targets linked to customers’ use of its fuels and affecting executive pay beginning in 2020. They move came after pressure from its activist investors.

BP and Total (NYSE: TOT) also have set short-term targets on reducing their own carbon dioxide emissions.

Meanwhile, two other groups of Exxon Mobil Corp. (NYSE: XOM) investors said they would file a shareholder resolution calling on the world’s largest oil company to set targets.