One question often asked of authors of books is, “How long did it take to write?” for many authors, myself included, this is a surprisingly difficult question to answer. It all depends on the starting point. Out of curiosity more than anything else, I started researching the UK’s onshore oil industry during the winter of 2014/15. This early research showed that to write a history of Britain’s onshore oil industry would be a huge undertaking and so I decided to concentrate on my home county of Dorset. Once I had secured a contract with Amberley Publishing in October 2019, writing began in earnest. A publisher’s deadline, May 2020 in my case, concentrated the mind wonderfully. Therefore, I suppose the answer to the question is, anytime from six months to five years.

I soon found out that information about Dorset’s oil came from a wide spectrum of sources ranging from; local and national newspaper archives, learned journals of archaeology, geology and engineering, central and local government databases, oil company publications, satellite imagery and personal contact with people. Bringing all this scattered information together provided at least one good reason to write this book.

The artist’s impression shown here makes the point rather well that oil is contained within the myriad pores of rock, rather like water in a sponge. If only one could wring out an oil-filled rock like a sponge! (© The Picture Now Image Collection/Mary Evans Picture Library, Dorset's Black Gold, Amberley Publishing)

A technical book like this one does require some background into the inevitable jargon used and this is provided in Chapter 2. I’ve incorporated some images of historical artworks and photographs by others to help explain technical terms used in later chapters.

The formation, trapping and subsequent discovery and production of oil is all about the geology. Fortunately, the world-renowned and much studied Jurassic Coast of Dorset and East Devon provides ample visual analogues of the geological features that go to make up the oil reservoirs of the Dorset oil fields. This geological setting is described in Chapter 3, illustrated by photographs of cliff sections and rock specimens.

Photograph of a cliff section outcrop of Bridport Sandstone at Burton Bradstock. It is an analogue of the oil-producing Bridport Sandstone reservoir in the Wytch Farm, Wareham and Waddock Cross oilfields. (Author, Dorset's Black Gold, Amberley Publishing)

It could be argued the history of Dorset’s oil starts at Kimmeridge during the mid-nineteenth century. Here, there is coastal exposure of an organic rich shale as part of the Kimmeridge Clay Formation. Pioneering work by James Young in Scotland found that a similar shale found in Mid Lothian could be made to produce oils and gases by heating it in closed retorts and condensing the vapours. His patented equipment and methods using Kimmeridge oil shale were quickly taken up by a number of entrepreneurs in Dorset during the 1850s. The successes and failures of these shale oil businesses are charted in Chapter 4 of the book.

Photograph of a scale model of James Young’s patented horizontal oil shale retort. Retorts like this were used in Dorset’s shale oil works at Wareham and Sandford. (Science and Society Picture Library, Dorset's Black Gold, Amberley Publishing)

The history of what is called conventional oil exploration and development, to distinguish it from shale oil and gas, starts onshore Dorset during the 1930s. It was during this time that oil company geologists realised the significance of the oil seeps found at various places along the Dorset coast from Osmington Mills to Mupe Bay. Subsequent drilling at cliff top sites at Kimmeridge and further inland, using fairly primitive drilling rigs, failed to find recoverable oil. It was after the end of the Second World War that exploration drilling resumed in Dorset. However, it wasn’t until BP returned to the cliff top at Kimmeridge in 1959 to drill the Kimmeridge 1 well that an oil discovery was made that produced oil to surface, thereby initiating the first oilfield in Dorset. Further conventional oil exploration took place in Dorset from 1960 onwards. To date, a total of 60 exploration oil wells have been drilled throughout the county. This activity has led to the discovery and subsequent development of four producing oilfields named, Kimmeridge, Wareham, Wytch Farm and Waddock Cross. Chapter 5 of the book describes the exploration drilling leading to these discoveries. Four separate chapters describe the development of each oilfield.

The development by BP of the Kimmeridge oilfield is described in Chapter 6. Here, it is explained how the drilling of four other wells did not produce any more oil in place, but instead showed the limited extent of the Kimmeridge reservoir. The chapter explains that this has presented something of an enigma, since the one producing well has been in production for sixty years and has produced more oil than was thought to exist originally. Some feasible explanations are discussed.

Photograph of the iconic ‘nodding donkey’ beam pump at the Kimmeridge 1 well site on the clifftop at Kimmeridge. This oil well has been producing oil for sixty years. (Author, Dorset's Black Gold, Amberley Publishing)

BP’s development of the Wareham oilfield is described in Chapter 7. Despite its discovery in 1964 by BP, attempts to develop the field didn’t start until, 1980 and then by British Gas not BP. The “stop go” development of this field is described leading to the first sustainable oil production in 1991, following an active campaign of drilling development wells by BP in 1990.

Dorset’s Wytch Farm oilfield has come to dominate the UK’s oil scene since it started production in 1979. At its peak of production, during 1995 to 1999, the oilfield contributed over 90 per cent to the UK’s total onshore oil production. Chapter 8 describes the stages in the development of this giant oilfield from its discovery in 1973 by British Gas through the pioneering developments by BP during its tenure as operator from 1985 to 2011. This chapter explains how BP developed innovative well technology to overcome the challenges presented in developing a large oilfield in an environmentally sensitive marine area of Dorset. Since 2011, the Wytch Farm oilfield has been operated by an Anglo-French company, Perenco, and has gone on to produce nearly 500 million barrels of oil out of an original 1 billion barrels in place.

Timeline of oil and water production from the Wytch Farm oilfield. Water cut is the percentage of water in the total fluids produced. (Author, contains information from the Oil and Gas Authority (OGA), Dorset's Black Gold, Amberley Publishing)

The Waddock Cross oilfield has, so far, proved to be the smallest in terms of oil production of the four Dorset oilfields. Chapter 9 describes its discovery in 1982 by British Gas and attempts by Egdon Resources plc as operator, more than twenty years later, to develop this oilfield. Despite efforts to produce oil during 2014 the field was shut-in in October due to lower than expected oil rates and much higher than expected water production. The operator asserts that further development of Waddock Cross is work in progress.

Alan Taylor's book Dorset's Black Gold is available for purchase now.