On Aug. 24, U.S. benchmark light crude West Texas Intermediate (WTI) closed at $38.24 a barrel — the lowest price level since February 2009. Brent crude was trading only a few dollars higher.

Revisiting global oil prices six months on from last time, I find no new narratives rocking the market. But we do see the prolonged pain of global shifts that have led to a deepening glut of supply and persistent weak demand. That leaves the outlook for producers looking bleak with the onset of autumn — a season not known for long road trips like the summer.

While the dynamics in play are complex, the stories can still be boiled down to three on the supply side: the U.S. shale boom, Iran and the Saudi-led OPEC policy. On the demand side is just one: China. On each of these points, we have not seen the adjustments we expected to prop up oil prices in the latter half of the year.

When the first signs of an oversupplied market were seen, oil price optimists hoped blindly for readjustments.

• So what if the shale revolution dumped millions of barrels of oil on the market? The resulting low oil prices will surely lead to well shutdowns and a global rebalancing.
• The re-emergence of Iran as an energy player? The nuclear deal may never be signed, and in any case the infrastructural turnaround needed to bring resources back on tap will take years.
• Saudis refusing to budge on OPEC production cuts? Surely they will give in.
• Downturn in China? That cannot last. China is an economic powerhouse that has kept the global economy, and global energy demand, propped up for a generation.

In all cases, the signals in recent months have led only to further saturation of the global oil and gas market and a gloomier outlook for producers in the near future.

The U.S. shale industry has shown surprising resilience to lower oil prices. According to oil services provider Baker Hughes, the fluctuating U.S. rig count — commonly used as a marker for industry activity — is currently at 885, half of last year's level.

More visibly, the notorious "boom towns" in Texas and North Dakota are not booming quite so vigorously. Stories abound of empty motels and the decline of what are known in industry jargon as "man camps" housing thousands of oilfield workers.

However, instead of cutting back on production, U.S. producers have used falling prices to cut costs rather than production, and housing expenses are some of the first budget lines to be cut by U.S. oil companies. U.S. shale production, while falling, is not falling dramatically enough to impact global oil prices.

Further afield, President Barack Obama has thrown all his resources into pushing through the nuclear deal with Iran in a bid to secure his presidential legacy. Some commentators were cynical about the viability of reaching an abiding deal with America's age-old enemy — a deal that in coming years could see a further flood of Iranian oil onto the market, subject to the restraints of its OPEC quota.

However, on July 14, Iran and the P5+1 signed a historic agreement that will lead to the gradual removal of sanctions on Iran's hydrocarbons industry in return for restrictions placed on the country's nuclear program. Contrary to expectations, oil prices rose slightly immediately following the deal, but once we enter 2016 we can expect accumulating Iranian production to begin putting further downward pressure on prices.

Iran's oil minister Bijan Zanganeh announced this week that the country would increase output by 500,000 barrels per day (bpd) as soon as restrictions are removed, and 500,000 bpd in the months after. The controversial deal faces a fierce battle to pass through a Republican-controlled Congress before it can be signed into law, but Obama has vowed to use the full force of his presidential veto.

Saudi Arabia, at the helm of the OPEC cartel, has historically been the global swing producer of oil. Its influence may have been diluted recently, but it remains the only country able to boost prices with a stroke of its pen by aligning the OPEC members to cut production or by cutting its own production quota.

The brave Saudi policy this year of maintaining production to defend market share, rather than cut output to support prices, has surprised many. Saudi Arabia is able to ride out prices under $60 a barrel for longer than others thanks to its hefty currency reserves, but the Financial Times reported the Saudis have dipped into their foreign reserves to the tune of $60 billion between August 2014 and April 2015, and the government has started borrowing for the first time since 2007.

Yet still they wait patiently for the U.S. shale industry to buckle.

However, some struggling OPEC members are beginning to view the strategy as less brave than foolhardy. Algeria, one of the cartel's weaker members, has lobbied for change, and several members have called for an emergency meeting. The death of King Abdullah in January gave rise to hopes that the new leaders would do a U-turn on the policy, but so far the Saudis are sticking to their guns despite growing signs of a looming domestic financial crisis.

We have taken surging demand in China for granted for many years. But China is facing its greatest challenge yet in transforming its break-neck export-led growth into more sustainable consumption-dominated growth.

The tremors in Chinese stocks at the beginning of this week, dubbed "Black Monday," brought home broader fears over the direction of the Chinese economy amid an economic slowdown. A downturn in China has serious implications for global energy, largely because it means a shortfall in the demand that energy markets are wired to expect from China.

Some analysts now speak of a "new normal" in China where we should ready ourselves for a sustained period of low Chinese growth, and minimal growth in energy imports for the next two to three years. Amid the current crisis, we cannot expect China to come to the rescue of global commodity prices.

Given past form, only a fool would predict oil prices in the short term. We have already seen a small spike in prices on the back of equity market recovery following panic in China.

Norwegian oil minister Tord Lien believes prices this below $40 are unsustainable. He may be right, but looking at the current direction of broad global trends, we are unlikely any time soon to see the convincing rebound in oil prices many have been waiting for.

The economic consequences for producing nations will continue be painful.